A pure chemical compound is a chemical substance that is composed of a particular set of molecules or ions that are chemically bonded.
Any salt, even though it reacts with water, will precipitate out completely when the water is completely evaporated. If you start with 50 grams of salt, you will end up with 50 grams of salt.
Answer:
It organizes all of the elements and it allows you to easily find the groups of elements such as
Group 1 of the periodic table consists of hydrogen and the alkali metals
Group 2 consists of the alkaline metals (batteries!)
Groups 3–12 contain transition metals
Groups 13–16 each contain at least one metalloid
Group 17 contains halogens
Group 18 consists of noble gases which are stable.
It is easy to read and theres a song to help you memorize them online.
Explanation: