In academic writing you need to be precise when you use information, dates or figures. Do not use "a lot of people" when you can say "50 million people".
For example:
Chemists had attempted to synthesize quinine for the previous hundred years but all they had achieved was to discover the extreme complexity of the problem.
The volatile oily liquid beta-chloro-beta-ethyl sulphide was first synthesized in 1854, and in 1887 it was reported to produce blisters if it touched the skin. It was called mustard gas and was used at Ypres in 19I7, when it caused many thousands of casualties.
It is approximately eight inches in length and runs from the urinary bladder, through the prostate gland, under the front of the pelvis, and, passing through the corpus spongiosum, it ends at the tip of the glans penis in an opening called the urethral meatus .