A. It has mass.
Air is matter, and can't be seen thus not all matter can be seen.
Any liquid or gaseous is matter (water, air, etc.)
Since it can be liquid or gaseous it doesn't have to maintain it's shape and size to be matter.
Steroids
are complex structure four connected rings of carbon atoms. They are cholesterol which is in all body cells and used to synthesize other steroids:sex hormones, such as estrogen, and testosterone and several hormones from the adrenal glands.
Waxes
are comprised of an ester of a long-chain alcohol and a fatty acid. Many plants have leaves and fruits with wax coatings to help prevent water loss.
Phospholipids
consist of Glycerol portion and fatty acid chains. Only two fatty acids chains; in place of the third is portion that include a phosphate group. THe phosphate portion is soluble in water [hydrophobic] forms the ''head'' of the molecule, while the fatty acids portion is insoluble in water [hydrophobic] and forms a ''tail''.
Fats
to store energy for cellular activities. Carbohydrates fat molecules are composed of carbon, hydrogen and oxygen atoms.
1/2 would be probability for couple to have baby boy
Answer:
Check if the rock layer has fossils in it.
Explanation:
The rock layer from the inside out and the fossils will tell you how old the rock is.
