Answer: Hydrogen and helium, both in the first period, have their valence electrons in the principal energy level n=1.
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Explanation:
C. Hydropower would need dams to be built, and this will prevent fishes from going upstream.
The cerebrum is part of the brain that controls the functions of the voluntary activity in the body. If an organism is smaller than another organism, for this case a frog and a rabbit. It means that the frog and the processes inside that body are less complex. Thus, the cerebrum do not need to be bigger than the cerebrum of a bigger organism.
Answer : The value of equilibrium constant (K) is, 0.004
Explanation :
First we have to calculate the concentration of 

and,

Now we have to calculate the value of equilibrium constant (K).
The given chemical reaction is:

Initial conc. 1.2 0 0
At eqm. (1.2-2x) 2x x
As we are given:
Concentration of
at equilibrium = x = 0.1 M
The expression for equilibrium constant is:
![K_c=\frac{[SO_2]^2[O_2]}{[SO_3]^2}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BSO_2%5D%5E2%5BO_2%5D%7D%7B%5BSO_3%5D%5E2%7D)
Now put all the given values in this expression, we get:



Thus, the value of equilibrium constant (K) is, 0.004