Critique my null and alternative hypothesis (beginner)

I'm new to writting these, so I want critique on if I'm doing them correctly and how I can write them better.

"You want to know if a drug works better than a placebo for it at increasing the number of the number of white blood cells."

$H_{0}$ = The population of white blood cells when given the drug is not significantly different to the population of white blood cells after taking the drug.

$H_{a}$ = The drug is statistically significantly better at increasing the number of white blood cells in the population.

Answer

Answers can be viewed only if
  1. The questioner was satisfied and accepted the answer, or
  2. The answer was disputed, but the judge evaluated it as 100% correct.
View the answer
The answer is accepted.