Answer:
The height of A is 900
Explanation: Beside A, there is a number which explains what the height is so the answer is A.
Answer:Protons are positively charged is the correct statement about an atom
I've also corrected the other statements
Atoms contain protons and neutrons in their nucleus
Neutrons posses no charge and are neutral
The nucleon number is the total number of protons and neutrons in a nucleus
Percentage recovery gives us an idea of the amount of pure substance recovered after the chemical reaction. Percentage recovery can be more than 100 % or less than 100 %. Usually, in any experiment performed the weight percentage recovery will be less than 100. Percent recovery values greater than 100 show that the recovered compound is contaminated.
Amount of acetaminophen initially taken = 350 mg
Amount of acetaminophen obtained after recovery =185 mg

= 
= 52.9%