C. The number of covalent bonds is equal to the number of unpaired valence electrons. For example, nitrogen and phosphorous both have 3 unpaired valence electrons thus forming 3 covalent bonds.
B, because as energy is move up form the phyramid, energy is lost.
Answer:
A
Explanation:
Earth revolves around the sun
I took a test on this
Answer:
1. Before: carbon dioxide After: Oxygen
2. Oxygen
3. Chloroplast
Answer: Nutrition
Explanation: Nutrients are the essential nourishments for growth and the maintenance of life.