Periodic table

6. there are 7 of them and they start on the left of the periodic table
8. negative charged particle in the atom
9. A substance that can flow freely but is of constant volume
10. The group that holds neon
14. Total number of protons and neutrons in the nucleus
16. any of the set of metallic elements occupying a central block
17. a substance or matter in a state in which it will expand freely to fill the whole of a container
18. any of a number of subatomic particles carrying a fractional electric charge

1. The electrons in the outermost shell of an atom
2. A element or substance that is not a metal
3. the number of protons in the nucleus
4. Neutrally charged particle in the atom
5. to or more forms of the same element that have equal numbers of protons but a different number of nuetrons
7. The group that holds lithium
8. A negative charge surrounding the atomic nucleus
11. Firm and stable in shape
12. smallest point of an element
13. The core of an atom that holds neutrons and protons
15. A positively charged particle in an atom