Why couple use a method of birth control

because it will control the birth of a child which can happen alot being overpopulated in the country or world. It also can mange their life and create a small and happy and healthy family.Also the child can get more love and support from their parents if they have less children and it wont be a taruma for the couple as well.  because growing a child can be expensive time costly and really hard.  

plz mark me as a brainlest a and thanks my answer

Explanation:

and btw i think the subject should be biology not chemestry

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.