1-why is it important that the small beaker that you are weighing is clean and try?

The beaker must be clean and dry without any impurities and water, because it would give us extra weight and lead to calculation errors

Have you ever noticed if the salt you're using says it's "iodized"? Iodine is a micronutrient, which means we need it in small quantities to be healthy. Because iodine is relatively rare in many people's normal diets, it's added to table salt. Then when people salt their food, such as tasty turkey, stuffing and mashed potatoes, they're also getting iodine. In this science activity you'll use some kitchen-friendly chemistry to investigate which types of salt have iodine and which don't.