Periodic Table

2. The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
5. The size of the atom
9. In chemistry, the _______ of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules
10. The temperature at which a liquid boils and turns to vapor.
11. ________, any of the six nonmetallic elements that constitute Group 17
12. A pattern of change
13. _______, any of the six chemical elements that comprise Group 2
15. Measure of the pull an atom has on an electron
17. As has been mentioned, March 1, 1869 is considered as the _______ of the Periodic Law.
18. Electrons on the outest/ biggest shell
19. _______ are natural materials that do not produce heat or electricity and that are structurally brittle
20. _______ is the ability of matter to combine chemically with other substances.

1. measures how strongly a Ve is held by the nucleus
3. __________ is the name given to the set of chemical properties associated with elements that are metals.
4. any of a group of rare gases that include helium, neon, argon, krypton, xenon, and sometimes radon and that exhibit great stability and extremely low reaction rates.
6. ________, any of the six chemical elements that make up Group 1
7. As its name implies, _______ is the act of emitting radiation spontaneously.
8. The _______ of an isotope and the relative isotopic mass refers to a certain specific isotope of an element.Density
14. In chemistry and atomic physics, an _______ may be thought of as an orbit followed by electrons around an atom's nucleus.
16. The ________ of a substance is the temperature at which it changes state from solid to liquid.