Answer:
Look at the properties of Oxygen and Silicon - the two most abundant elements in the Earth's crust - by clicking on their symbols on the Periodic Table.
Explanation:
Volume= Mass/ Density= 20/184
= 0.108 cubic cm
The reasonable ground-state electron configuration is: 1s2 2s2 2p6 3s2 3p6 4s2 4d8
The answer is C. condenses
