How do you calculate the abundance of an atom and the relative atomic maths? as simply as possible?

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

If i add water to oil what will happen

Which factor is likely to impact the possible number of compounds ?