True or false a. very little oxygen and nitrogen are found in air.
b. oxygen is the main cause of the formation of rust in iron.
c. impure air is odourless.
d. plants take in oxygen gas during respiration.
e. air contains water vapour.

true or false

a. very little oxygen and nitrogen are found in air. false

b. oxygen is the main cause of the formation of rust in iron.   false

c.  impure air is odourless true

.d.  plants take in oxygen gas during respiration. true

e. air contains water vapour. true

Explanation:

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.