<h3>
Answer:</h3>
0.75 moles NaOH
<h3>
Explanation:</h3>
We are given;
Volume of NaOH solution = 2.5 Liters
Molarity of NaOH = 0.300 M
We are required to calculate the moles of NaOH
We need to establish the relationship between moles, molarity and volume of a solution.
That would be;
Concentration/molarity = Moles ÷ Volume
Therefore;
Moles = Concentration × Volume
Thus;
Moles of NaOH = 0.300 moles × 2.50 L
= 0.75 moles
Therefore, the number of moles of NaOH is 0.75 moles
Answer : The mass defect required to release energy is 6111.111 kg
Explanation :
To calculate the mass defect for given energy released, we use Einstein's equation:

E = Energy released = 
= mass change = ?
c = speed of light = 
Now put all the given values in above equation, we get:


Therefore, the mass defect required to release energy is 6111.111 kg
Answer: -
The approximate number of atoms in a bacterium is 10¹¹
Explanation: -
We are given the mass of a bacterium is 10⁻¹⁵ kg.
We are told that the mass of a hydrogen atom is 10⁻²⁷ kg.
Finally we learn that the average mass of an atom of the bacterium is ten times the mass of a hydrogen atom.
Mass of an atom of bacterium = 10 x mass of hydrogen atom
= 10 x 10⁻²⁷ kg.
= 10⁻²⁶ kg.
Thus the number of atoms in a bacterium = 
= 
= 10¹¹