Answer:
There is one single covalent bond between two carbon atoms.
Explanation:
We know that sharing of electrons form covalent bonds.
If we look upon K,L,M ,N shells of the carbon and hydrogen atoms.
We found that Hydrogen is having only 
electron in K shell.
And Carbon on the other hand is having 
electrons in K shell and 
electrons in L shell.
So carbon have valence electrons,and it can share bonds with any relevant atom to complete its octet.
And Hydrogen requires electron to complete its doublet.
Alkane general formula 
For ethane 
Carbon atom is shared by 
Hydrogen.
The remaining one electron 
of carbon will be shared with another carbon atom.
An image of the sharing of electrons attached below,
Hence we have only covalent bond between the two.
Answer:
the answer is B its common sense
Explanation:
H - 1.01
C - 12.01
0 - 16.00
2(1.01) + 12.01 + 2(16.00) = 46.03 g/mol
A.
This is because BaSO₄ has the lowest solubility product out of all the substances.
-101, K=C+273 so in this you would subtract 273 from 172
