1. Period Two
TRENDS

2. Atomic Mass- mass of an atomLi
6.941amu Be
9.012amu B
10.811amu C
12.00amu N
14.00amu O
16.00amu F
18.99amu Ne
20.18amu

3. Atomic size- radius of an atomLi
167pm Be
112pm B
87pm C
67pm N
56pm O
48pm F
42pm Ne
38pm

4. reactivity- ability of an element to undergo chemical changes
Reacts with water Be
Does not react with water B
Does not react with oxygen C N
Not very reactive O
Reacts slowly with metal F
Explodes upon contact with metals Ne
Unreactive

5. Shielding effect- full core shells blocking the positive nuclear force from reaching the valence shell Li 2 Be B C N O F Ne

6. Ionization energy- energy required to remove an electronLi
520 Be
900 B
800 C
1090 N
1400 O
1310 F
1680 Ne
2080

7. Electronegativity- tendency of an atom to attract electronsLi 1 Be
1.5 B
2.0 C
2.5 N
3.0 O
3.5 F
4.0 Ne --