Which of the following statements is/are not true for Basalt? i. Basalt is highly reactive to chemical weathering. ii. Basalt is an igneous rock formed from the rapid cooling of lava. iii. Basalt has high compressive strength, making it suitable for road and building construction.
- AOnly (i)Correct
- BOnly (ii)
- COnly (ii) and (iii)
- D(i), (ii) and (iii)
Solution
Concept
Properties and characteristics of basalt rock
Formula
NONE
Step-by-step solution
1. Basalt is an igneous rock formed by the rapid cooling of lava. Answer: A
Explanation
Basalt is a dense, hard igneous rock formed from the rapid cooling of lava, featuring high compressive strength and strong resistance to weathering. Statement i incorrectly claims that basalt is highly reactive to chemical weathering, whereas statements ii and iii are accurate properties. Thus, statement i is the only false statement, making option A correct.
Why the other options are wrong
C) Statement (iii) is true, so statement (iii) cannot be classified as untrue. D) Statements (i) and (iii) are true statements about basalt.
Shortcut
Basalt is durable and highly resistant (not reactive) to chemical weathering.
Common mistake
Misreading the negative question phrasing ("not true") and selecting option C or D containing the statements that are true about Basalt.
Correct answer: A) Only (i)