One difference between mixtures and pure substances is that
a)
mixtures can be physically separated.
b)
mixtures are made of one type of atom.
c)
pure substances have no chemical bonds.
d)
pure substances can be physically separated.

Option (A) is the correct answer.

Explanation:

A mixture is defined as the substance that contains two or more different number of substances which are physically mixed together.

For example, a mixture of mud and water can be separated through the process of filtration.

A pure substance is defined as the substance which contains either same or different type of atoms that are chemically combined to each other in a fixed ratio by mass.

For example, both and are pure substances.

A pure substance can only be separated by chemical means.

Thus, we can conclude that one difference between mixtures and pure substances is that mixtures can be physically separated.

≅200-130 milions years ago pangea splited in 2 continents

it cools slower in the earth meaning the crystals have more time to form than lava on the surface