H.W1-OXIDATION NUMBER

Oxidation number of Fe in Fe²⁺ ion:

• 0

• -2

• +2

• +3

Which element has the same oxidation number in all of its compounds?

• oxygen

• fluorine

• hydrogen

• chlorine

Oxidation number of S in S₈

• 0

• +2

• -4

• +6

Element that only has a stable oxidation number of +1:

• Na

• Cl

• Ca

• Al

What is the oxidation number of an atom of nitrogen in the compound N₂?

• 0

• +3

• -3

• -6

What is the oxidation number of phosphorus in H₃PO₄?

• +1

• +4

• +5

• +8

What is the oxidation number of Fe in FeO?

• +1

• -1

• +2

• -2

What is oxidation number of Cr in

Cr₂O₇^-2

• -2

• +2

• +6

• +12

If an atom loses electrons during a chemical reaction, the atom was:

• Oxidized

• Reduced

• Neutralized

• Precipitated

Oxidation number of O in the compound H₂O₂

• 0

• -1

• -2

• +2