BIOCHEMISTRY
POLAR AND NONPOLAR MOLECULES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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4
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7
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2
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6
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Detailed explanation-1: -Hence the number of valence electron in calcium is 2 electrons.
Detailed explanation-2: -Ca2+ represents an ion with 20 protons and 18 electrons. A calcium atom has 20 protons and 20 electrons. The 2+ charge next to the symbol indicates a loss of two electrons: 20-2=18.
Detailed explanation-3: -*Note that helium (He) only has two valence electrons.
Detailed explanation-4: -Calcium is in group 2. The valency of a group 2 element is decided by the number of valence electrons. Here, the number of valence electrons in calcium is 2. Therefore, the valency is 2.
Detailed explanation-5: -Chlorine is in Group VIIA (Group 17), so it would have seven valence electrons. Calcium would have two valence electrons, since it is in Group IIA (Group 2). Helium is the only exception for the main group elements. The first energy level holds a maximum of two valence electrons.