Given :
a.
b.
c.
d.
.
To Find :
Find the most likely vale of x for each one .
Solution :
a .
Because boron have valency of 3 .
So , x = 3 .
b . 
Valency of carbon is 4 .
x = 4 .
c . 
Valency of nitrogen is 3 .
Therefore , x = 3 .
d . 
Now ,we know valency of carbon is 4 and hydrogen is 1 .
Also , two hydrogen are already there .
So , only 2 electrons left to share .
Since , chlorine have valency of 1 .
Therefore , only 2 electrons of chlorine can connect .
x = 2 .
Hence , this is the required solution .
Answer:- 71.7 calories
Solution:- it is a unit conversion problem where we need to convert joules into calories.
The unit conversion for these energy units is:
1 calorie = 4.184 joule
The given energy is 300 joules and has to be converted to calories. We will show the set up using dimensional analysis.

= 71.7 calories
So, the energy in calories is 71.7.
There should be 2 since there’s 2 D atoms in the reaction.
Answer:
Somatotropin(Growth Hormone)
Explanation:
-Uncontrolled growth in a person is usually caused by the excessive secretion of growth hormone.
-This hormone is also known as Somatotropin.
-This hormone is produced in the pituitary gland.