Answer:
d. A water particle and an air particle
Explanation:
The force of gravity (F) between two objects of masses m1 and m2 and separated by a distance r is given as:

where G is the gravitational constant
This force is therefore, directly proportional to the masses and inversely related to the distance between them.
Based on the given options, since the masses of the water and air particles are very small (masses of earth, moon and sun is relatively huge), the gravitational force between them would be negligible and difficult to measure.
Answers are:
Catabolism:
- g<span>enerally exergonic (spontaneous): In this reactions energy is released.
- </span><span>convert NAD+ to NADH. Electrons and protons released in reactions are attached to NAD+.
- </span><span>generation of ATP. ATP is synthesis from ADP.
- </span><span>convert large compounds to smaller compounds. Foe example starch to monosaccaharides.
Anabolism:
</span><span>- convert NADPH to NADP+. Protons and electrons are used to make chemical bonds.
</span>- <span>convert small compounds to larger compounds.</span>
Answer:
A. Mafic; iron and/or magnesium
Explanation:
Let's find the answer by naming some minerals and their chemistry.
Mafic minerals are dark-colored whereas felsic minerals are light-colored, thats way mafic rocks are dark-colored because they are mainly composed by mafic minerals and the other way around for felsic rocks.
But remember that mafic minerals as amphiboles, pyroxenes or biotites, involve in their chemical structure iron and/or magnesium. Although calcium and sodium can be incorporated in amphiboles and clinopyroxenes, they are not involved in orthopyroxenes and biotites. On the other hand, although potassium is involved in biotite and in some extent in amphiboles, this element is not involved in pyroxenes.
So in conclusion, mafic minerals are usually dark-colored because they involve iron and/or magnesium in their chemical structures.
What classification system????