Question 13 Which of the following is an example of hormonal endocrine stimulation? a) The secretion of cortisol in response to elevated levels of ACTH in the blood.
b) PTH released in response to low levels of Ca++ in the blood.
c) GnRH stimulating the release of gonadotropins by the anterior pituitary.
d) The adenohypophysis releasing LH to increase progesterone secretion by the ovaries.
e) GHRH triggering the release of GH

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.