chemistry question. what is your opinion?

Question

Given the same mass of each substance, why are the number of molecules present not the same?

Answer 1

Because each atom has different number or protons, neutrons in the nucleus and different number of electron shells, so the vary in size. And that means so do the molecules, and also some molecules can be rather simple like H2 or relatively huge like a large hydrocarbon.

Answer 2

Put simply, different individual atoms have different weights, known as RAM (relative atomic mass).

So, for example 10 grams of iron hydrogen (atomic mass of 1) will have lots more H2 molecules than say, 10 grams of cabon (atomic mass 12).

If you wanna know how many atoms in a gram, that's Avagadro's number - (atomic mass) x 10^24.

So in 10 gram of hydrogen, there's 100000000000000000000000000 atoms, but in 10 grams of carbon there's only 120000000000000000000000000. So, lots.

Answer 3

Different substances generally have different molecular masses.For equal masses of different substances,

n1*m1 = M = n2m2
so
n1/n2 = m2/m2