C) The mountain lion population would drop below its current level.
The two are potassium and rubidium. Why? Na is an alkali metal. As you go down the metals become more reactive.
Calcium has 20 protons. Why? The atomic # is 20 (the one at the top).
It has 20 neutrons. Why? The atomic mass (the number on the bottom) is ~40, ignoring electron mass. 40- 20 protons = 20 neutrons.
It has 20 electrons.
Why? The # of protons and electrons is the same. Ions aren't on the periodic table.
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Answer:
The definition of trade off is an exchange where you give up one thing in order to get something else that you also desire. An example of a trade off is when you have to put up with a half hour commute in order to make more money.
Explanation:
