If the earth's differentiation were any different, it may have affected its gravitational pull both of these factors were essential to creating our atmosphere. temperature, tectonic activity, heat transfer.

Is there any opitions? if you have the periodic table, the noble gases are 8a family, the halogen are the 7a family, and the nonmetal are  carbon, nitrogen, phosphorus, oxygen, sulfur, selenium, fluorine, chlorine, bromine, iodine and astatine.

Answertechnician (a) is correct;

How are period and frequency related to each other? dperiod is the reciprocal of frequency.