Answer: The answer is b.
Explanation: The flowers are one of the most differentiating features of angiosperms. They are the reproductive structures of angiosperms. The flower has a thalamus that is a short axis and four whorls of sporophylls arranged on the thalamus. The four whorls of floral leaves include calyx, corolla, androecium and gymnocium.
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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