Given a scientific question, generate a correct answer to it.

Input: Consider Input: Adding the number of protons plus the number of neutrons in an atom, decides it's approximate mass, what is another word for this value?

Output: atomic number

Input: Consider Input: What is the tube-like device used to reliably measure lower levels of radiation?

Output: geiger counter

Input: Consider Input: At high altitudes, acclimatization increases red blood cells, so there is more what to help transport the available oxygen?
Output: hemoglobin