If the oxide contains 7.17 % o by mass, what is the identity of the metal?

Answer is: the identity of the metal is lead (Pb).

ω(O) = 7.17% ÷ 100%.

ω(O) = 0.0717; mass percentage of oxygen in the oxide.

If we take 100 grams of compound:

1) m(O) = ω(O) · 100 g.

m(O) = 0.0717 · 100 g.

m(O) = 7.17 g; mass of oxygen in the oxide.

n(O) = m(O) ÷ M(O).

n(O) = 7.17 g ÷ 16 g/mol,

n(O) = 0.448 mol; amount of oxygen.

2) m(M) = 100 g - 7.17 g.

m(M) = 92.83 g; mass of metal in the oxide.

n(O) = n(M) = 0.448 mol.

M(M) = m(M) ÷ n(M).

M(M) = 92.83 g ÷ 0.448 mol.

M(M) =207.20 g/mol; molar mass of the metal.

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.