Question

Assertion (A): Sial appears to float above Sima.

Reason (R): Sial has lower density than Sima.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R does not explain A.

• A is true but R is false.

• A is false but R is true.

Answer 1

Both A and R are true and R is the correct explanation of A.

Explanation:

• Assertion (A) is correct because SIAL (Silica and Aluminium) forms the continental crust, which is less dense and appears to “float” above the denser oceanic crust formed by SIMA (Silica and Magnesium).
• Reason (R) is also true because SIAL is indeed less dense than SIMA, which explains why SIAL “floats” on top of SIMA, similar to how less dense material floats above denser material. Therefore, both the assertion and the reason are correct, and the reason correctly explains the assertion.