Which is the heaviest metal among the following?
1). Gold
2). Silver
3). Iron
4). Copper
2. Oxygen which is vital for life is a product of photosynthesis and conies from
4. The most abundant element in the earth’s atmosphere is
5. Earth's crust mainly contains ______.
6. An example of replenshible energy source is
7. Which amongst the following is not a Cation?
8. Major portion of the earth’s crust is mainly constituted by