Answer:
"nonmetal, nonmetal"
Explanation:
Oxygen is a non metal and Nitrogen is a non metal. It is 8th element of the periodic table. It is located in period 2 and group 16.
Nitrogen lies at the group 15 of the periodic table. Its atomic no is 7. Its valency is 2.
Hence, the correct option is (c) "nonmetal, nonmetal".
64: C
65: D because weathering is defined as rock being eroded/changed
hope i could help
Answer:
there are three Fluorine atom. This is because Nitrogen give 3 electron away but fluorine can only take 1. So nitrogen gives 1 neutron to 3 fluorine each which makes it a stable compound
Answer : The equilibrium concentration of
in the solution is, 
Explanation :
The dissociation of acid reaction is:

Initial conc. c 0 0
At eqm. c-x x x
Given:
c = 

The expression of dissociation constant of acid is:
![K_a=\frac{[H_3O^+][C_6H_5COO^-]}{[C_6H_5COOH]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BC_6H_5COO%5E-%5D%7D%7B%5BC_6H_5COOH%5D%7D)

Now put all the given values in this expression, we get:
![6.3\times 10^{-5}=\frac{(x)\times (x)}{[(7.0\times 10^{-2})-x]}](https://tex.z-dn.net/?f=6.3%5Ctimes%2010%5E%7B-5%7D%3D%5Cfrac%7B%28x%29%5Ctimes%20%28x%29%7D%7B%5B%287.0%5Ctimes%2010%5E%7B-2%7D%29-x%5D%7D)

Thus, the equilibrium concentration of
in the solution is, 