Because in SI, the expectation is that area and volume will be expressed in terms of a linear dimension( the metre) or its multiples.
Answer:this is all i found out
Oxygen is known as a diatomic molecule. Oxygen atom has atomic number as 8 so it has its K shell completely filled with 2 electrons. While it has only 6 electrons in L shell which requires 8 electrons to get inert gas configuration. So oxygen atom shares 2 electrons with another oxygen atom to form a diatomic molecule.
Explanation:
The equation is balanced as follows
Mgcl2 +2AgNo3 -->2Agcl +Mg(No3)2
from equation above 1 mole of MgCl2 reacted with 2 moles of AgNo3 to form 2 moles of AgCl2 and 1 mole of Mg(NO3)2
when balancing equation the number of atom of element should be the same on each side of equation.