Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.
Example:
There are 5g of water.
Calculate the amount of moles.
The water's formula is H2O, so the molar mass of it is

g/mol.
The amount of moles is:
5g ÷ 18g/mol ~ 0.28mol
Answer:
D
Explanation:I alredy know this i am in 7th gread
The molecule have TETRAHEDRAL HYBRID ORBITAL.
SP3 hybridization involves the mixing of one orbital of S sub level and three orbitals of P sub level of the valence shell. All the orbitals possess equivalent energies and shapes. The SP3 orbital has 25% S character and 75% P character. S and P refers to the s and p sub shells.<span />
The molecule for ethane is C2H6. or CH3-CH3.
Carbon LOVES hydrogen. If possible, Carbon would have four bonds attach to hydrogens. IN this molecule, one of the bond is used to attach a carbon to another carbon, so instead of 4 hydrogens, each carbon would have 3 hydrogens..