Answer:
liquid
Explanation:
19. 1, 2, 3, 4, 5, 6, 7, 8
20. Li=1+, Be=2+, B=3+, C=4+
21. N=3-, O=2-, F=1-
D.2NaBr+CaF 2NaF CaBr2
43 i think
15 8 O ---> 15 7 N + 0 1 e
Element: Oxygen
Mass Number: 16 u
Decay: Beta
238 92 U ----> 234 90 Th + -4 -2 e
Element: Uranium
Mass Number: 238.051 u
Decay: Alpha