Why is there an increase in heart rate and breathing during exercise

the heart must pump more blood to other places of the body

Explanation:

Explanation:

As you exercise energy and oxygen are needed by the muscles to work, therefore the faster you move the quicker your heart beats inorder to supply the muscles you are using with energy and oxygen.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.