IMPORTANT QUESTION ON METAL , AND METALLOIDS ( you want to know but don't know)

1) Most abundant metal in earth crust : aluminium.

2)2nd most abundant metal in earth crust : iron .

3) most abundant element in universe : hydrogen .

4) Most abundant element in human body:  oxygen.

5) Most abundant mineral in human body : calcium .

6)Most abundant metalloids found in earth crust : silicon crust.

7) Rarest element in earth crust : Astatine.

8) Haviest metal in earth crust  : Osmium .

9) Haviest element in earth crust : Uranium .

10) lightest metal in earth crust : Lithium .

11) Lightest element in earth crust : Lithium 

12) hardest metal : platenum

13) Cobalt -60 is used to treatment of cancer .

14) Light emitted in firefly is due to burning of white phosphorous .

15) excess eating of chocolate is harmful due to Nickel & lead present in it .