Question

Give Reasons for the following :
1.Igneous Rocks are also called Primary Rocks.
2.Extusive Igneous Rocks have generally small crystals.
3.Rocks are of great economic Significance. ​

Answer 1

आग्नयें चट्टानों की उत्पत्ति सर्वप्रथम होती है इसलिए उन्हें प्राथमिक चट्टाने भी कहते हैं

अत्यधिक गर्म होने के कारण धातु पिघल जाते हैं जिनसे उनका आकार छोटा रह जाता है

चट्टानों में पेट्रोल कोयला धातु और अत्यधिक मूल्यवान वस्तुएं मिलती हैं जो हमारी अर्थव्यवस्था के लिए उपयोगी होती हैं

Answer 2

1. As igneous rocks are formed from magma and begin the rock cycle, they are called primary rocks.

2.Intrusive igneous rocks cool from magma slowly because they are buried beneath the surface, so they have large crystals.

3.Rocks are of great economic significance Some of the main benefits of rocks are as follows : After disintegration, they turn into valuable soils. They are the store-houses of a large number of minerals. They are the source of precious metals like gold, silver, platinum etc.