What earth of earth is made of molten material?crust, inner core, outer core or mante?

Outer core.

The outer core consists of super-heated liquid molten lava. The lava is mostly made up of iron and nickel, which is why some geologists call it molten metal instead of molten rock.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.