Calculate the electronegativity difference for the following bonds: CO² H₂0 NO₃⁻¹ SO₄⁻²
NH₄⁺¹ ClO₂⁻¹ NH₂Cl XeF₆

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.

Answerhund's rule;