4
5
6
10
11
4
5
6
10
11
4
5
6
10
11
7
8
9
10
18
7
8
9
10
18
7
8
9
10
18
Neon
Sodium
Magnesium
Carbon
Oxygen
20
21
22
23
24
10
11
12
21
23
-2
-1
0
+1
+2
Ions
Radicals
Isotopes
Acids
Neutrons
18
19
20
21
22
18
19
20
21
22
42
Ca
+2
Ca and 42
Ca, 42, and +2