# Number Density Formula, Calculator, Calculation With Example

### Number Density Calculator:

With our number density calculator, you can estimate the charge carrier number density of specific metals.

Recently, copper is the electrical conductor of choice in almost every branch of electrical wiring. We can find it almost everywhere. That is why we have also made example calculations of the charge carrier density of copper.

Divide the product by the molar mass of the substance to find the charge carrier number density.

Number density is defined as an intensity quantity used to describe the concentration of countable objects such as molecules, particles, cells, phonons, galaxies, and others.

Students can use our number density calculator to find the charge carrier density of metals. A charge carrier is a particle that carries an electrical charge when current flows.

### Number Density Formula:

Number Density formula n(c/m3) in carrier per meter3 is equal  to the the Avogadro constant Na(mol) in mol and multiply the density of the material p(kg/m3) in kilogram per meter3 and multiply the number of free electrons per atom M(g/mol) in gram per mole.Hence the Number Density formula can be written as

n(c/m3)=Na(mol) *p(kg/m3) * x /M(g/mol)

where,

n=is the charge carrier number density

x=is the number of free electrons per atom

M=is the molar mass

Na= is the Avogadro constant Na=6.0221 *1023 1 /mol

P=is the density of the material

### Example:1

The number of free electrons and density of copper is  15 and 23 kg /m3  .Find the number density of copper?

Given that

Density of copper p =23 kg /m3

Number of free electrons in copper x =15

Molar mass of copper M= 28 g /mol

By using formula

n=Na *p * x /M

n=6.0221 *1023  * 23 *15 /28

n=0.7420087 *1028 carriers /m3

### Example:2

The number of free electrons and density of copper is 250  and 350 kg /m3  .Find the number density of copper?

Given that

Density of copper p =350 kg /m3

Number of free electrons in copper x =250

Molar mass of copper M= 18 g /mol