What does it mean to use all appropriate senses to observe?
A. Don't look at things that you're not told to.
B. Follow your teacher's instructions at all times.
C. Taste can never be used to make observations.
D. Ask an adult before observing using smell, taste, or touch.

what are the two models

explanation:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.