How many valence electrons in a sulfide atom? Sulfide ion? HPO4²-?

Question

All three of them.
last one is monohydrogen phosphate i think

Answer 1

A sulfUR atom (no such thing as a sulfide atom) has 6 valence electrons.

A sulfide ion is S with a -2 charge. The -2 charge means an additional 2 electrons are added to the sulfur atom, so it has a total of 8 valence electrons.

For the last ion, the H contributes 1 valence electron, the P contributes 5, each O contributes 6 and the -2 charge means that there are two additional valence electrons. This adds up as:
1 + 5 + 4(6) + 2 = 32 valence electrons.

The valence electrons for neutral atoms that are in groups 1A through 8 A is determined by the group number. For example, I know that sulfur and oxygen each have 6 valence electrons because they're both in group 6A.

Answer 2

6