Answer:
Both are breathing muscles
Explanation:
When rib muscles and the diaphragm contract they increase the volume of the chest cavity, increasing the air pressure outside the body, causing air to rush into the lungs to fill the vacuum created by the increase in volume.
Answer:
any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the nucleus, or different atomic weights. There are 275 isotopes of the 81 stable elements, in addition to over 800 radioactive isotopes, and every element has known isotopic forms. Isotopes of a single element possess almost identical properties.
Explanation:
