What is a diaphragm? What does it do?

The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.

Explanation:

Diaphragm contracts and expands when you breathe air

A diaphragm on a microscope is the piece that enables the user to adjust the amount of light that is focused under the specimen being observed. A diaphragm is typically found on higher-power microscopes versus less expensive or toy models. The diaphragm is located directly under the stage or platform where user places the specimen or slide.

Explanation:

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;