In the context of internal structure how does density generally change from surface to centre?

Correct answer: Generally increases

The direct answer is B: density generally increases from the surface toward the centre of Earth. Density means how much mass is packed into a given volume. The reasoning is: the crust is made largely of relatively lighter rocks; deeper layers contain denser materials under enormous pressure; the mantle is denser than the crust, and the core contains very heavy metallic materials, mainly iron and nickel. Therefore the general pattern is increasing density inward, although density does not change in a perfectly smooth way at every boundary. Option A is wrong because density does not generally decrease toward the centre. Option B is correct because the deepest interior is the densest major region. Option C is wrong because matter does not become zero at the centre. Option D is wrong because different layers have different compositions and pressures. Memory cue: “deeper Earth, heavier material.”