The earth's basins are sinking because of:

folding
sedimentation
glacier melting
all of the above

The earth's basins are sinking because of : All of the above
Folding , Glacier melting, and sedimentation all caused Tectonic subsidence, which cause the sinking of Earth's crust on a large scale

hope this helps

It won't lose or gain electrons if it's a covalent bond it shares the electrons with another atom or atoms. if it is an ionic bond it will lose the 3 electrons on the outer shell and become a positively charged ion.  credit goes to @sunshinebaby of answers.yahoo.com.