Concept explainers
- A. The first shell corresponds to the first energy level, and it can hold up to 2 electrons. Hydrogen has one proton, so it has 1 electron and one vacancy. A helium atom has 2 protons, 2 electrons, and no vacancies.
- B. The second shell corresponds to the second energy level, and it can hold up to 8 electrons. Carbon has 6 electrons, so its first shell is full. Its second shell has 4 electrons and four vacancies. Oxygen has 8 electrons and two vacancies. Neon has 10 electrons and no vacancies.
- C. The third shell corresponds to the third energy level, and it can hold up to 8 electrons. A sodium atom has 11 electrons, so its first two shells are full; the third shell has one electron. Thus, sodium has seven vacancies. Chlorine has 17 electrons and one vacancy. Argon has 18 electrons and no vacancies.
Figure It Out: Which of these models have unpaired electrons in their outer shell?
The atoms are referred to as building blocks of all substances. In other words, it is the basic fundamental unit of the matter. In every atom, the uncharged neutron and positively charged protons are present in the nucleus whereas the negatively charged electron moves around the nucleus. Generally, the shell model system is used to study the valence status of an atom. The atomic number is the number of protons present in the atom which determines the type of the atom
Explanation of Solution
The given shell model consists of about eight atoms namely helium, neon, hydrogen, oxygen, carbon, sodium, chloride, and argon. Of this given atom in the model the hydrogen, carbon, oxygen, chlorine and sodium have unpaired electrons in the outer shell. These unpaired electrons are available to pair with other unpaired electrons in another atom. Thus these atoms combine to form molecules.
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Chapter 2 Solutions
Biology Today and Tomorrow without Physiology (MindTap Course List)
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