pH is the measure of the concentration of hydrogen ions in a solution
Answer:
I think it is the last one.
Explanation:
I am not sure because i am stuck on this one, too.
Answer:
carbon has four unpaired electrons in its valence shell . hydrogen having one unpaired electron in its valence shell comes to bond with carbon by sharing a pair of electrons .since carbon needs 4 electrons to be stable, 4 hydrogen atoms take part in the bond . It's a covalent bond because the difference between the electronegativity of carbon and hydrogen is quite small .