Answer:
Three (3) => 2Na⁺ and 1SO₄²⁻
Explanation:
Na₂SO₄ => 2Na⁺ + SO₄²⁻
Note: one can easily determine the cation-anion separation during aqueous ionization if one reads the formula left to right => place an imaginary line after the 1st metal of the molecular formula => left of line is cation and right of line anion.
Na₂SO₄ => Na₂ | SO₄ => 2Na⁺ + SO₄²⁻ (3 ions)
CaCO₃ => Ca | CO₃ => Ca₂⁺ + CO₃²⁻ (2 ions)
Ni(NO₃)₂ => Ni | (NO₃)₂ => Ni²⁺ + 2NO₃⁻ (3 ions)
Ca₃(PO₄)₂ => Ca₃ | (PO₄)₂ => 3Ca²⁺ + 2PO₄³⁻ (5 ions)
