An iron washer is heated. State the effect on its:

(i) mass

(ii) internal diameter

(iii) external diameter and

(iv) density.

(i) Mass does not change on heating.

(ii) When iron washer is heated, it expands so internal diameter increases.

(iii) External diameter increases as iron washer expands on heating.

(iv) Density decreases as volume of the iron washer increases on heating.