Answer:
Elements in which the d-sublevel is being filled have the properties of metals
Basalt is more dense than granite because granite is made of lighter mass.
Answer:
Formula of magnesium oxide is MgO and formula of strontium oxide is SrO
Explanation:
Ca, Mg and Sr are same group bivalent metals.
Oxygen is a bivalent element
In general, formula of a compound made of a cation
and an anion
is
for 
When x = y, formula of the compound becomes MA
As both these metals and oxygen are bivalent therefore formula of magnesium oxide is MgO and formula of strontium oxide is SrO.
The answer is a day, a year is the earth's revolution around the sun