Atoms and Molecules

What is formula unit mass? How is it different from molecular mass?

What is the ratio by mass of combining elements in H₂O, CO₂ and NH₃?

What is meant by atomic mass, gram atomic mass of an element? Why is the mass have different expressions i.e., 'u' and 'g'?

Write down the formula for:

Copper nitrate, calcium sulphate and aluminium hydroxide.

What is polyatomic ton? Give one example.

Consider the compound calcium carbonate (CaCO₃).

 (a) Name the elements present in calcium carbonate.

 (b) Calculate its formula unit mass. (Atomic masses: Ca = 40u, C = 12u, O = 16u)

(c) If a sample of calcium carbonate contains 6.022 × 10²³ formula units, what would be its mass in grams?

What is atomic mass unit?

Define valency and give the valency for the following elements:

Explain law of constant proportion.

Give the Latin name for sodium, potassium, gold and mercury.

Give the atomicity of phosphorous and nitrogen.