Forming and balancing equations

Question 1

Why do equations need to be balanced?

Answer 1

• Mass cannot be created or destroyed in a chemical reaction.
  –> Balancing ensures the correct ratio of substances involved in a reaction, making the equation scientifically accurate.

Question 2

What are diatomic molecules?

Answer 2

Diatomic molecules are made up of two atoms of the same element.

H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂

Examples: H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂

Question 3

What are polyatomic molecules?

Answer 3

Polyatomic molecules are made up of three or more atoms that are chemically bonded together.

P₄, S₈, Se₈

Examples: P₄, S₈, Se₈

Question 4

What are polyatomic ions?

Answer 4

Polyatomic ions are made up of multiple atoms that are bonded together and have a charge.

Ammonium
- NH₄⁺

Nitrite
- NO₂⁻

Nitrate
- NO₃⁻

Sulfite
- SO₃²⁻

Sulfate
- SO₄²⁻

Hydroxide
- OH⁻

Phosphate
- PO₄³⁻

Carbonate
- CO₃²⁻

Chlorate
- ClO₃⁻

Acetate
- C₂H₃O₂⁻ (or CH₃COO⁻)

Question 5

What are state symbols?

Answer 5

State symbols show the physical state of substances in a reaction.

• (s) for solid
• (l) for liquid
• (g) for gas
• (aq) for aqueous (dissolved in water)

Common state symbols: (s) for solid, (l) for liquid, (g) for gas, (aq) for aqueous (dissolved in water)