Answer:
Sound waves are used for measurement in hertz.
Explanation:
Answer: The balanced equation for the given reaction is
.
Explanation:
A chemical equation which contains same number of atoms on both reactant and product side.
For example, 
Here, number of atoms on reactant side are as follows.
Number of atoms on product side are as follows.
To balance this equation, multiply
by 2 on reactant side and multiply
by 2. Hence, the equation will be re-written as follows.

Here, number of atoms on reactant side are as follows.
Number of atoms on product side are as follows.
Now, there are same number of atoms on both reactant and product side. So, this equation is balanced.
Thus, we can conclude that the balanced equation for the given reaction is
.
Answer:
Therefore the equilibrium number of vacancies per unit cubic meter =2.34×10²⁴ vacancies/ mole
Explanation:
The equilibrium number of of vacancies is denoted by
.
It is depends on
- total no. of atomic number(N)
- energy required for vacancy
- Boltzmann's constant (k)= 8.62×10⁻⁵ev K⁻¹
- temperature (T).

To find equilibrium number of of vacancies we have find N.

Here ρ= 8.45 g/cm³ =8.45 ×10⁶m³
= Avogadro Number = 6.023×10²³
= 63.5 g/mole

g/mole
Here
=0.9 ev/atom , T= 1000k
Therefore the equilibrium number of vacancies per unit cubic meter,

=2.34×10²⁴ vacancies/ mole