Why did oceans not exist on earth nearly 4 billion years ago?
a. no water molecules were present.
b. water remained a gas because earth was very hot.
c. water existed as ice because earth was very cold.
d. there was no oxygen gas in the atmosphere

grav potential energy

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.