What could the fourth quantum number of a 2s2 electron be? O A. ms=0
O B. me = -1
O c. m = +1
O D. mg = +
1
2

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.

a:

by the combination of an unlimited number of elements

the correct answer is:

a. formation of precipitation

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.