Explain the factors that affect population size

Define each of the factors that influence the size of a biological population:

• Birth: Number of new individuals that are generated in a population, or frequency with which individuals (organisms) produce offspring, causing the increase in the size of a population.

• Mortality: Quantity or frequency with which the organisms of a population die, causing the decrease in their size.

• Immigration: Income of individuals of the same species to a population, coming from another site, increasing the number or size of the population that receives immigrants.

• Emigration: Departure of individuals from one population to another, causing the decrease in their size.

The Growth Rate of a population, also called Population Change, will depend on the factors defined above and is calculated through the following mathematical formula:

Population Change: (Birth + Immigration) - (Mortality + Emigration)

When the sum of the mortality rate plus emigration is greater than the birth rate plus immigration, this means that the population tends to decrease, but if the birth rate plus immigration is higher than the mortality and emigration rate, the population will tend to increase

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)