Which best describes how igneous rocks are formed?

a.
layers of dirt and other rocks are pressed together to form igneous rocks.

b.
molten material in the earth cools and hardens to form igneous rocks.

c.
elements in the earth form igneous solids with crystals.

d.
wind erodes mountains into small igneous rocks.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.