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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Fats must be broken down into fatty acids before being converted into glucose. Lipids are known as the back up energy source. They are used to make enzymes, hormones, and antibodies.
Answer:
A
Explanation:
photosynthesis converts light energy to chemical energy and not the other way round
product of photosynthesis is oxygen and energy
photosynthesis cannot occur is light energy is not available
Answer:
the third one
Explanation:
physical change is only on looks