The basic unit of matter is:
an element
a mixture
an atom
a compound

Based on the topographic map of mt. st. helens, what is the contour interval of the volcano about height is 2,950 m?

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

In the presence of oxygen, glycolysis is followed a. the krebs cycle b. lactic acid fermentation c. alcoholic fermentation d. photosynthesis