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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It allows them to study and analyze the species.
Answer:
Ur answer is D. They should grow native plants on the lodging property to attract local wildlife.
Explanation:
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Answer:
Arteries at at a higher pressure than veins.
Explanation:
Arteries receive blood after the heart beats, putting them at a higher pressure. They are also thicker than veins as well.
