A plastic bag so that it can be cleanly put in
Valence shell
The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms. This outermost shell is known as the valence shell, and the electrons found in it are called valence electrons.
So they respond by releasing hormones that stimulate the body to retain sodium and water. Blood vessels fill with additional fluid, and blood pressure goes up. The narrowing in one or both renal arteries is most often caused by atherosclerosis, or hardening of the arteries.
This is a physics question, not biology, but...
f=1/T where f is frequency and T is the period.
f= 1/(1/3)=3
frequency =3 Hz
