/Retail Sales Associate/ Interview Questions
JUNIOR LEVEL

Tell me about a time when you had to handle a customer's complaint about a missing product or item.

Retail Sales Associate Interview Questions
Tell me about a time when you had to handle a customer's complaint about a missing product or item.

Sample answer to the question

One time, a customer came into our store and complained about a missing product. I apologized and asked for more details. The customer explained that they had purchased the product online and it was supposed to be delivered to their house, but it never arrived. I checked our system and confirmed that the product had been shipped. I then offered to track the package and contact the shipping company to find out what happened. After a few phone calls, I discovered that the package had been delivered to the wrong address. I immediately contacted the customer and informed them of the situation. I apologized for the inconvenience and assured them that we would rectify the situation. I arranged for the correct product to be shipped to the customer's address and offered them a discount on their next purchase as a gesture of goodwill. The customer was appreciative of the prompt response and resolution.

A more solid answer

One time, a customer visited our store and approached me with a complaint about a missing product they had ordered online. I empathized with the customer and assured them that I would do my best to resolve the issue. I asked for their order details and checked our system to confirm that the product had been shipped. Upon further investigation, I discovered that the package had been delivered to the wrong address. I immediately contacted the shipping company and provided them with the correct address. While waiting for the package to be retrieved, I kept the customer updated on the progress and offered them alternative options to fulfill their immediate needs. Once the package was retrieved, I arranged for it to be delivered to the customer's address at no additional cost. To compensate for the inconvenience caused, I also offered the customer a discount on their next purchase. The customer expressed appreciation for the prompt and proactive resolution of the issue.

Why this is a more solid answer:

The solid answer provides more specific details about the problem-solving process and the customer service provided. It demonstrates a proactive approach to resolving the issue and keeping the customer updated on the progress. However, it could still be improved by highlighting the candidate's adaptability and flexibility, as well as their attention to detail in ensuring the correct address was provided to the shipping company.

An exceptional answer

During my time as a retail sales associate, I encountered a situation where a customer approached me with a complaint about a missing product they had recently ordered online. I immediately acknowledged the customer's frustration and assured them that I would personally handle the situation to ensure a satisfactory resolution. I carefully listened to the customer's account of the issue and obtained the necessary order details to investigate further. Upon reviewing our system, I confirmed that the product had indeed been shipped, but there seemed to be a delivery discrepancy. Utilizing my attention to detail, I cross-referenced the customer's shipping address with the address provided to the shipping company, only to discover that there was a minor error in the address input. Understanding the urgency of the matter, I swiftly contacted the shipping company and provided them with the correct address, ensuring that the package would be redirected without delay. Throughout the process, I maintained regular communication with the customer, keeping them informed of the steps being taken and offering alternative solutions to meet their immediate needs. I also took the opportunity to educate the customer about our inventory procedures to avoid similar issues in the future. Finally, I arranged for the missing product to be expedited to the customer's corrected address at our expense as a gesture of goodwill. By going above and beyond to rectify the situation and providing exceptional customer service, I was able to transform a complaint into a positive experience for the customer.

Why this is an exceptional answer:

The exceptional answer excels in providing specific details about the candidate's problem-solving skills, attention to detail, and customer service orientation. It showcases the candidate's proactive approach in identifying the address discrepancy and their ability to effectively communicate with the customer throughout the process. Additionally, the candidate takes the opportunity to educate the customer about inventory procedures to prevent future issues. This answer demonstrates the candidate's enthusiasm for learning product knowledge and solidifies their qualifications for the role.

How to prepare for this question

  • Familiarize yourself with the company's inventory procedures and processes to effectively handle customer complaints about missing products.
  • Practice active listening to understand the customer's concerns and gather all necessary information to investigate the issue.
  • Develop problem-solving skills by reviewing past experiences where you successfully resolved a customer complaint.
  • Learn to communicate clearly and confidently with customers, ensuring that they are updated on the progress of resolving their complaint.
  • Understand the impact of your actions on customer satisfaction and be prepared to go the extra mile to exceed their expectations.

What interviewers are evaluating

  • Customer service orientation
  • Problem-solving skills

Related Interview Questions

More questions for Retail Sales Associate interviews

Tell me about a time when you had to educate a customer about the unique or premium features of a product variation or model.
What do you do to ensure that you are providing a personalized and tailored experience for each customer?
What measures do you take to ensure the accuracy and security of cash handling and financial transactions?
What would you do if you noticed a coworker engaging in unethical sales practices?
How do you handle situations where a customer is dissatisfied with the value or performance of a specific product or service?
What steps do you take to ensure the sales area is clean and organized?
How do you handle working with difficult or demanding coworkers?
Describe a time when you had to quickly learn about a new product or service to assist a customer.
Describe a time when you had to collaborate with a coworker to find a creative or innovative solution for a customer's problem or request.
Describe a time when you had to handle a customer complaint.
What steps do you take to ensure accuracy and efficiency when processing sales transactions?
Tell me about a situation where you had to handle a customer's complaint with limited available alternatives or options.
What do you do to create a positive and welcoming atmosphere for customers?
How do you handle situations where a customer is dissatisfied with the return or exchange policy?
How do you handle feedback or criticism from supervisors or customers?
What do you find most challenging about working in a retail sales role?
What steps do you take to provide exceptional customer service?
What steps do you take to ensure the sales area is visually appealing and attractive to customers?
How do you ensure that you stay organized and on top of your tasks as a retail sales associate?
How do you handle situations where a customer is dissatisfied with the availability of a product?
Tell me about a time when you had to adapt your communication style to accommodate a customer's preferences.
Describe a situation where you had to work collaboratively with coworkers from different departments to fulfill a customer's unique request or requirement.
How do you handle situations where a customer is dissatisfied with the availability or accessibility of a product or service?
Tell me about a time when you had to handle a customer's complaint with limited available inventory.
How do you handle situations where a customer is dissatisfied with the durability or longevity of a product?
How do you handle situations where a customer's request or need is outside of your area of expertise?
How do you handle situations where a customer is dissatisfied with the availability or selection of a specific product or service?
What measures do you take to ensure accuracy and efficiency when processing cash transactions and financial transactions?
How do you handle situations where a customer wants to return or exchange a product?
What strategies do you use to understand and meet customer needs?
What do you do to ensure the security and integrity of cash and credit card transactions?
How do you handle situations where you are unable to meet a customer's request or need?
What do you do to maintain a positive attitude and enthusiasm for your work as a retail sales associate?
How do you handle situations where your teammates are not pulling their weight?
How do you handle multitasking in a fast-paced retail environment?
How would you handle a difficult or irate customer?
Describe your experience with inventory procedures.
Tell me about a time when you had to educate a customer about the environmental or social impact of a product.
Describe a time when you had to collaborate with a coworker to find a customized or tailored solution for a customer's unique preferences or requirements.
How do you handle situations where a customer is dissatisfied with the value or cost-effectiveness of a product or service?
How do you handle situations where a customer is dissatisfied with the availability or accessibility of a specific service or product?
Describe a time when you had to communicate with a customer who had limited English proficiency.
Tell me about a time when you had to educate a customer about the functionality or features of a product.
Tell me about a time when you had to make a quick decision to resolve a customer issue.
What measures do you take to ensure accuracy and efficiency when processing cash and credit card transactions?
How do you handle situations where a customer is dissatisfied with the performance or effectiveness of a product or service?
Describe a time when you had to handle a customer's complaint with limited resources or options.
Tell me about a time when you had to educate a customer about the unique or innovative features of a product.
What would you do if you noticed a coworker mishandling or mistreating merchandise?
How do you handle situations where you have to work with limited resources or inventory?
How do you handle situations where a customer is dissatisfied with the customer service they received from a coworker?
How do you handle situations where a customer is dissatisfied with their purchase?
Describe a difficult interaction you had with a coworker and how you resolved it.
Tell me about a time when you had to educate a customer about the functionality or compatibility of a product.
How do you handle situations where a customer is dissatisfied with the variety or selection of products available?
Tell me about a time when you had to educate a customer about the features or benefits of a specific product variation or option.
How do you handle situations where a customer is dissatisfied with the pricing or cost of a specific product or service?
How do you approach teamwork and collaboration in a retail setting?
How do you handle stressful situations in the workplace?
What measures do you take to ensure a positive and friendly attitude towards customers?
Tell me about a time when you had to think creatively to solve a problem for a customer.
What do you do to ensure that customers feel valued and appreciated during their interactions with you?
How do you handle situations where a customer is dissatisfied with the availability or selection of a specific product?
Describe a situation where you had to collaborate with a coworker to find a unique or tailored solution for a customer's needs.
Describe a situation where you had to solve a customer problem.
Tell me about a time when you had to educate a customer about the unique or advanced features of a product variation or model.
Describe a situation where you had to work collaboratively with coworkers from different departments to meet a customer's urgent or specific request.
How do you handle situations where you have to work under the supervision of a challenging or difficult manager?
How do you handle situations where a customer is dissatisfied with the pricing or promotional offers?
How do you handle stress and pressure in the workplace?
Tell me about a time when you had to handle a customer's complaint about a damaged or defective product.
What measures do you take to ensure the accuracy and completeness of customer orders, requests, and preferences?
What strategies do you use to handle customer complaints and ensure customer satisfaction?
What measures do you take to prevent errors and ensure the accuracy of customer orders and requests?
Tell me about a situation where you had to handle a customer's complaint with limited available options or resources.
How do you handle situations where a customer is dissatisfied with the variety or selection of a particular product or service?
Tell me about a time when you had to educate a customer about the benefits or advantages of a specific product feature.
Can you explain the steps you would take to prepare merchandise for purchase or rental?
Describe a situation where you had to work collaboratively with a coworker to resolve a customer's complex request or issue.
Tell me about a time when you had to handle a customer's complaint about a product that was out of stock.
How do you handle situations where multiple customers are seeking assistance at the same time?
Describe a situation where you had to resolve a dispute between coworkers.
How do you handle situations where a customer is dissatisfied with the value or return on investment of a specific product or service?
How do you handle situations where a customer is dissatisfied with the value or return on investment of a specific product?
Can you explain the importance of excellent communication and interpersonal skills in a retail sales role?
Tell me about a time when you had to educate a customer about the safety or reliability of a product.
Tell me about a time when you had to educate a customer about a product's durability or warranty.
How do you handle situations where a customer is dissatisfied with their overall experience at the store?
Describe a situation where you had to handle a customer's request for an unconventional or unique item.
Describe a time when you had to work on a project or task with tight deadlines and limited resources.
How do you handle situations where a customer is dissatisfied with the selection or variety of a particular product?
How do you handle situations where a customer is dissatisfied with the service they received from a supervisor?
Tell me about a time when you had to handle a customer's complaint about an out-of-stock product.
Describe a situation where you had to work collaboratively with coworkers from different departments to meet a customer's urgent or specific request or requirement.
Describe a time when you had to collaborate with coworkers from different departments to resolve a complex customer issue.
What do you do to create a positive and welcoming experience for customers with diverse backgrounds or needs?
What steps do you take to ensure the accuracy of inventory records?
What would you do if you noticed a coworker regularly failing to follow proper sales procedures?
Tell me about a situation where you had to work with a difficult or challenging customer.
Tell me about a time when you had to educate a customer about the performance or efficiency of a product.
Describe a time when you had to collaborate with a coworker from a different department to overcome a complex or challenging customer request.
Tell me about a time when you had to educate a customer about the features and benefits of a product.
Tell me about a situation where you had to work in a fast-paced environment with tight deadlines.
How do you handle situations where a customer is dissatisfied with the service they received?
What measures do you take to ensure accuracy and security when processing cash transactions?
How do you handle situations where you have limited knowledge or expertise about a product or service?
Describe your experience working in a retail environment.
What do you do to ensure accuracy and organization when managing inventory and stock levels?
Tell me about a time when you turned a dissatisfied customer into a loyal customer.
Describe a time when you had to collaborate with a coworker to find a creative solution to a customer's problem.
How do you handle cash transactions? Do you have any experience with cash-handling?
Are you comfortable with physical tasks such as stocking merchandise and lifting weights up to 20-50 pounds?
How do you handle situations where a customer is dissatisfied with the selection or variety of products?
How do you handle situations where you have to deliver bad news or disappointing information to a customer?
Tell me about a situation where you had to educate a customer about a product's sustainability or eco-friendly features.
Tell me about a time when you had to go above and beyond to accommodate a customer with specific needs or requests.
Describe a time when you had to collaborate with coworkers from different departments to fulfill a customer's unique request or requirement.
Describe a situation where you had to work collaboratively with a coworker from a different department to accommodate a customer's specific needs.
What do you do to ensure the accuracy and completeness of customer orders and preferences?
Describe a situation where you had to handle a customer's request with limited available options.
Describe a situation where you had to handle a customer's request for a specialized or customized product.
Do you have any experience with sales quotas? How do you work towards achieving them?
Tell me about a situation where you had to handle a customer's complaint with limited available solutions.
Describe a time when you had to handle a high volume of customer inquiries or requests.
What measures do you take to ensure the safety and security of customers and coworkers?
What are your strategies for upselling or recommending additional products to customers?
Tell me about a time when you had to educate a customer about a product's compatibility or system requirements.
What measures do you take to ensure accuracy and efficiency when processing cash transactions?
What do you do to ensure accuracy and attention to detail when handling cash transactions?
Describe a time when you had to collaborate with a difficult or demanding customer to find a mutually satisfactory solution.
What would you do if you noticed a coworker engaging in discriminatory behavior towards a customer?
How do you handle situations where you have to deliver unfavorable news to a customer?
How do you handle situations where you are unable to meet a sales quota?
How do you handle situations where a customer is dissatisfied with the customer service they received?
Tell me about a situation where you had to handle a customer's complaint with limited available options.
Describe a time when you had to collaborate with a coworker to find a mutually beneficial solution for a customer's needs.
What steps do you take to ensure the accuracy and completeness of customer orders and requests?
What do you do to ensure accuracy and efficiency when managing inventory and stock levels?
What measures do you take to ensure accuracy and security when processing cash transactions and financial transactions?
Tell me about a time when you had to educate a customer about the unique or special features of a product variation or model.
Describe a time when you had to handle a high-stakes or high-pressure sales negotiation.
Can you describe a situation where you had to work with limited supervision?
What measures do you take to ensure the accuracy and efficiency of order fulfillment and delivery?
Describe a time when you successfully resolved a conflict between a coworker and a customer.
Describe a time when you had to work with difficult or challenging coworkers to achieve a common goal.
How do you stay updated on current sales and promotions?
Tell me about your experience with point-of-sale systems and cash registers.
Tell me about a time when you had to educate a customer about the environmental or ethical qualities of a product.
What do you do to ensure accuracy and timeliness when managing inventory and restocking?
Have you ever had to deal with theft or security risks in a retail setting? If so, how did you handle it?
Have you ever had to deal with a particularly challenging or difficult customer? How did you handle the situation?
How do you handle situations where you make a mistake in a cash transaction?
Describe a time when you had to collaborate with coworkers from different departments to overcome a specific customer challenge.
What steps do you take to ensure the security and integrity of cash transactions?
What do you do to ensure that you consistently provide a welcoming and positive atmosphere for customers?
What do you do to create a positive and welcoming environment for customers with different preferences or expectations?
How do you handle situations where a customer is dissatisfied with the speed or efficiency of service?
Tell me about a time when you had to educate a customer about the benefits or advantages of a specific product feature or functionality.
Describe a time when you had to handle a customer's complaint about a defective or damaged product.
Have you ever had to make a difficult decision at work? How did you handle it?
Do you have any experience with product knowledge training? How do you stay knowledgeable about the products you sell?
What do you do to stay calm and composed when dealing with irate customers?
Tell me about a situation where you had to handle a customer's complaint without any prior knowledge of the issue.
What steps do you take to ensure accuracy in handling cash and making change for customers?
Describe a situation where you had to work collaboratively with a coworker to complete a sale.
How do you handle situations where a customer wants to return or exchange an item without a receipt?
How do you handle situations where a customer is dissatisfied with the value or quality of a product or service?
Describe a time when you had to handle a customer's request for a hard-to-find or specialty item.
Tell me about a situation where you had to handle a customer's request for a product or service that was not traditionally offered.
How do you handle situations where a customer wants a refund or exchange but does not have the original packaging?
Describe a time when you had to handle a customer's complaint with limited information or resources.
How do you handle situations where a customer is dissatisfied with the accessibility or convenience of a service?
What steps do you take to ensure that customer orders are accurate and delivered in a timely manner?
Describe a time when you had to collaborate with a coworker to find a customized or tailored solution for a customer's specific needs or requirements.
What do you do to ensure that you understand and comply with security practices in a retail environment?
How do you prioritize and manage your time in a retail sales setting?
How do you handle situations where a customer is dissatisfied with the value or return on investment of a product?
What steps do you take to ensure the accuracy and efficiency of sales transactions when processing multiple purchases?
Describe a time when you had to collaborate with a coworker to find a tailored or customized solution for a customer's unique requirements or preferences.
How do you handle situations where a customer is dissatisfied with the variety or selection of a specific product or service?
What steps do you take to ensure the accuracy and promptness of customer refunds?
How do you handle situations where a customer is unhappy with the delivery or installation of a product?
Tell me about a time when you had to adapt to a new sales technique or strategy.
Tell me about a situation where you had to handle a customer's complaint without any supervision.
Describe a time when you had to collaborate with a coworker from a different department to find a solution for a customer's specific needs or preferences.
How do you handle situations where you are unable to accommodate a customer due to inventory or other constraints?
Describe a situation where you had to work collaboratively with a coworker from a different department to meet a customer's specific and unique needs.
What do you do to ensure accuracy and organization when managing merchandise displays and promotions?
What measures do you take to prevent theft or security risks in a retail setting?
Describe a time when you had to collaborate with a coworker to find a customized or tailored solution for a customer's unique preferences or needs.
Describe a time when you had to handle a high-pressure sales situation.
Tell me about a time when you had to follow a specific inventory procedure.
What do you do to ensure the security and accuracy of cash handling and financial transactions?
What techniques do you use to upsell or cross-sell products to customers?
Tell me about a time when you had to work with limited inventory or product availability.
Tell me about a time when you had to educate a customer about a product's unique features or benefits.
Tell me about a time when you had to work collaboratively with a team to resolve a customer issue.
Tell me about a situation where you had to handle a customer's complaint with limited available options or alternatives.
Tell me about a situation where you had to handle a customer's complaint about a product that was not in stock.
How do you handle situations where a customer is dissatisfied with the availability or selection of a particular product or service?
Describe a time when you had to collaborate with coworkers from different departments to fulfill a customer request.
Can you give an example of a time when you went above and beyond to exceed sales goals?
Describe a situation where you had to work closely with a teammate to achieve a sales goal.
Tell me about a situation where you had to handle a customer's complaint with limited information or resources.
What measures do you take to ensure that merchandise is properly tagged and labeled?
Describe a time when you had to collaborate with a coworker to find a customized or personalized solution for a customer's needs or preferences.
Describe a situation where you had to work collaboratively with a coworker from a different department to meet a customer's specific and unique request.
How do you handle situations where a customer is dissatisfied with the speed or efficiency of a specific service?
How do you handle situations where a customer is dissatisfied with the service or response they received from a coworker?
Describe a time when you had to handle a customer's complaint about a billing or invoicing error.
What measures do you take to ensure the accuracy and efficiency of cash handling and financial transactions?
Describe a situation where you had to handle a customer's request for a product or service that was not currently available.
What measures do you take to ensure the accuracy and security of cash and credit transactions?
Tell me about a time when you had to handle a customer's request for a refund or exchange.
Describe a time when you had to handle a difficult or demanding customer while juggling other responsibilities.
How do you handle situations where a customer is dissatisfied with the service they received from a coworker?
What measures do you take to ensure the accuracy and completeness of inventory records and tracking?
What steps do you take to ensure the accuracy and completeness of customer orders?
What do you do to ensure accuracy and efficiency when processing exchanges or returns for customers?
What measures do you take to ensure the accuracy and efficiency of cash and credit card transactions?
Tell me about a situation where you had to handle a customer's complaint with limited available alternatives.
Tell me about a time when you had to educate a customer about the unique or additional features of a specific product variation or model.
Tell me about a time when you had to adapt to a change in the retail environment.
What do you do to ensure the accuracy and timeliness of inventory management and tracking?
Tell me about a time when you had to handle a customer's complaint about a misleading or false advertisement.
How do you handle situations where a customer wants a refund or exchange but does not have a receipt?
Tell me about a time when you had to educate a customer about the efficiency or time-saving benefits of a product.
Describe a time when you had to collaborate with coworkers from different departments to resolve a customer complaint.
Tell me about a situation where you had to handle a customer's complaint with limited available alternatives or solutions.
What do you consider to be the most important qualities of a successful retail sales associate?
What steps do you take to ensure the accuracy of your cash transactions?
What do you do to ensure the accuracy and timeliness of order fulfillment and delivery?
Describe a time when you had to collaborate with a coworker from a different department to fulfill a customer's request.
Describe a situation where you had to work collaboratively with a coworker from a different department to fulfill a complex customer request.
Describe a time when you had to handle multiple customers with competing needs at the same time.
Tell me about a time when you had to think quickly and problem-solve in a retail sales role.
Describe a time when you had to work collaboratively with coworkers from different departments to resolve a customer's issue or complaint.
How do you handle situations where you have to communicate bad news or disappointing information to a customer?
Tell me about a situation where you had to handle a customer's complaint about a delayed or late delivery.
How do you handle situations where a customer is dissatisfied with the ease or convenience of a particular service?
What steps do you take to ensure that you are following proper security procedures in a retail environment?
Tell me about a situation where you had to handle a customer's complaint with limited resources or options.
Can you describe a time when you had to handle a difficult customer in a calm and professional manner?
How do you handle situations where a customer is unhappy with the pricing of a product?
What measures do you take to ensure that merchandise is properly displayed and presented to customers?
Describe a time when you had to work with a difficult or challenging supervisor.
Tell me about a time when you had to handle a customer's complaint about a billing or pricing error.
What measures do you take to ensure the accuracy and integrity of merchandise displays?
Tell me about a time when you had to educate a customer about a product or service.
Tell me about your familiarity with customer and market dynamics.
Tell me about a time when you had to educate a customer about the convenience or time-saving benefits of a product feature.
Tell me about a time when you had to handle a customer's complaint about a missing product or item.
Tell me about a time when you had to collaborate with coworkers from different departments to complete a sale.
Describe a time when you had to collaborate with coworkers from different departments to meet a customer's needs.
Describe a situation where you had to work collaboratively with coworkers from different departments to overcome a customer's unique challenge or request.
How do you stay motivated and enthusiastic about learning product knowledge?
Describe a situation where you had to handle a customer's request for a discontinued or hard-to-find item.
How do you handle situations where a customer is dissatisfied with the condition or quality of a product?
Describe a situation where you had to work collaboratively with a coworker from a different department to fulfill a customer's unique or specific request or requirement.
What do you do to ensure a positive and enjoyable shopping experience for customers with different backgrounds and preferences?
Describe a time when you had to collaborate with coworkers from different departments to find a creative solution for a customer's complex request.
What do you do to maintain a positive and professional demeanor when dealing with difficult or demanding customers?
Describe a time when you had to collaborate with a customer to find a solution to their unique needs.
Tell me about a situation where you had to handle a customer's complaint with limited information or product knowledge.
How do you handle situations where a customer is dissatisfied with the policies or procedures of the store?
What strategies do you use to manage your time effectively in a busy retail sales environment?
Tell me about a time when you had to go above and beyond to meet a customer's specific needs.
How do you handle situations where a customer is dissatisfied with the quality of customer service they received?
Describe a situation where you had to handle a customer's request for a discontinued or out-of-season item.
How do you handle situations where a customer is dissatisfied with the quality of a product?
How do you handle situations where a customer is dissatisfied with the reliability or effectiveness of a service?
Tell me about a time when you had to handle a customer's complaint with limited information or knowledge.
How do you handle situations where a customer is dissatisfied with the return or exchange process?
Describe a time when you had to collaborate with a coworker to find a creative or innovative solution for a customer's specific needs or preferences.
Tell me about a time when you had to educate a customer about the unique features or advantages of a product.
What steps do you take to ensure the security and accuracy of customer payments and transactions?
Tell me about a situation where you had to handle a customer's complaint with limited options or solutions.
What measures do you take to ensure the accuracy and availability of inventory for customer orders?
How do you handle situations where a customer is dissatisfied with the accessibility or convenience of a particular service or product?
How do you handle situations where a customer is dissatisfied with the responsiveness or timeliness of service?
Tell me about a situation where you had to educate a customer about the value or cost-effectiveness of a product.
Describe a situation where you had to work collaboratively with coworkers from different departments to meet a customer's unique needs.
Describe a situation where you had to handle a customer's request for a customized or personalized product.
What do you do to ensure accuracy and efficiency when processing customer orders and requests?
Back to all questions