1.
Which of the following was to be discovered first in the chromospheres of the sun?

2.
Most soluble in water is:

3.
The most important ore of aluminum is

4.
The two elements that are frequently used for making transistors are:

5.
Actinides are the elements with atomic numbers from

6.
What is laughing gas?

7.
From which mineral is radium obtained?

8.
Which of the following are the ingredients of gun metal?

9.
Marsh gas is

10.
Permanent hardness of water can be removed by adding:

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