Second is the si base unit for measuring
a.)time
b.)length
c.)volume
d.)mass

a.)time

Explanation:

IN the international system time is measured in seconds, this is often used by scientifics more than regular people, since most of the measures of time that regular people use are often in hours or minutes, but for the international system the base for time is always in seconds.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.