1. Suppose you design an experiment to study the amount of growth shown by plants exposed to different types of fertilizer. You use 3 different fertilizer brands on tomato plants that you keep in individually enclosed chambers
to collect the oxygen they each produce.
a. State the null hypothesis of this experiment.
b. Identify the following variables:
independent variable
dependent variable
c. Describe an appropriate control treatment for this experiment.

cancer   is   essentially   uncontrolled   mitosis   of specialized cells

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.

c. heat from the poles back down towards the equator.