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.
I believe that the answer is Noble Gases. I hope this helps. :)
Answer:
3 grams
Explanation:
14 g of N2 is 1/2 mole
If you halve the N2 in the balanced equation , you have to halve the H2 down to 1.5 moles of H2 which is 3 grams
Answer:
The correct answer is - option C. Law of superposition.
Explanation:
According to the law of superposition states that within a sequence of layers of natural sedimentary rock without any disturbance, the oldest layer is lies under the younger layers with ascending order in the sequence.
If a sedimentary rock has 4 layers as a, b, c and d where the younger layer d would be on top and the oldest layer a would be at the bottoms.
Thus, the correct answer is - option C.
