Question

Which of the following statements is not true about igneous rocks?
a. It formed crystals.
b. It is formed from magma.
c. It can become glassy in appearance.
d. It can be formed from an existing rock.​

Answer 1

Answer:C

Explanation:

Answer 2

Option d, "It can be formed from an existing rock" is the incorrect statement.

• Igneous rocks are produced when the magma (molten ores present beneath the Earth's surface) cools down and solidifies.
• This often happens during volcanic eruptions, when magma escapes the inner layers of the earth.
• The temperature difference between the outer surface and inner surface of the planet causes the cooling of the magma.
• The cooling crystallizes the magma too.
• Examples of igneous rocks are: granite, basalt, obsidian. Most of these rocks are coarse grained and appear to be glassy.