Question

Total how many atoms are present in the formula $C{a_3}{(P{O_4})_2}$?
A.$5$
B.$8$
C.$9$
D.$12$
E.$13$

Answer 1

Molecule: The substance which is formed by the same type of elements i.e. same metals or same non-metal.
Compound: The substance which is formed by two or more different elements are known as compounds.

Complete step by step solution:
Let us first talk about what atoms are.
Atoms: They are defined as the smallest particle of any substance. They cannot be broken into pieces further. Atoms consist of three types of elements i.e. electrons, protons and neutrons.
Element: It is defined as the smallest part of any substance. They are made of the same type of atoms. They are basically of two types i.e. metals and non-metals. For example: hydrogen, carbon, oxygen, etc.
Here we are given with the compound i.e. $C{a_3}{(P{O_4})_2}$. And we have to find the total number of atoms present in the compound. From here we can see that there $3$ calcium atoms i.e. $Ca$ present in this compound. Along with calcium atoms phosphorus (represented by $P$) and oxygen (represented by $O$ ) are also present. Here the number of phosphorus atoms is $2$ and the number of oxygen atoms in the compound is $8$. So the total number of atoms present in the compound is $3 + 2 + 8 = 13$.

So, option E is correct.

Note:
Atomic mass: The mass of an atom is known as atomic mass. It is represented by the symbol ${\text{A}}$.
Atomic number: It is defined as the number of protons in an atom. It is represented by the symbol $Z$.