Atoms 2022

1. sum of protons and neutrons
4. a pure substance made of only one kind of atom
8. a one or two letter representation of an element
10. a change in a substance that does not change its identity
11. a subatomic particle that has no charge and is found in the nucleus of an atom
12. smallest particle of an element
13. a subatomic particle that has a positive charge and is found in the nucleus of an atom
15. the number of protons in the nucleus of an atom

2. a change the occurs when one or more substances change into entirely new substances with different properties
3. a table that classifies elements by their physical and chemical properties
5. the law that states that mass cannot be created or destroyed in ordinary chemical and physical changes
6. a subatomic particle that has a negative charge
7. a characteristic that can be observed without changing the identity of the substance
9. a characteristic of a pure substance that describes its ability to change into different substances
14. the center of an atom