Which of the following factors determines the size of an atom?
A. the volume of the nucleus
B. the volume of space occupied by the electrons of the atom
C. the volume of a single electron, multiplied by the number of electrons in the atom
D. the total nuclear charge
E. the total mass of the electrons surrounding the nucleus
Answer (2)
The size of an atom is determined by the space occupied by its electrons.
The nucleus is too small to significantly affect the atom's size.
Nuclear charge and electron mass have indirect effects.
Therefore, the correct answer is (b). $\boxed{b}
Explanation
Problem Analysis Let's analyze the question. We need to determine which factor primarily determines the size of an atom from the given options.
Analyzing Options (a) The volume of the nucleus: The nucleus is very small compared to the overall size of the atom. Therefore, the volume of the nucleus does not determine the size of the atom. (b) The volume of space occupied by the electrons of the atom: Electrons are spread out around the nucleus, and the space they occupy largely defines the atom's size. This seems like a plausible answer. (c) The volume of a single electron, multiplied by the number of electrons in the atom: While the number of electrons is relevant, it's the space they occupy, not their individual volumes, that matters most. (d) The total nuclear charge: Nuclear charge affects the electron configuration, but it doesn't directly determine the size. (e) The total mass of the electrons surrounding the nucleus: The mass of electrons doesn't directly define the atom's size.
Determining the Answer Based on the analysis, the volume of space occupied by the electrons of the atom is the primary factor determining the size of the atom.
Examples
Understanding the size of atoms is crucial in chemistry and materials science. For example, the size of atoms affects how they pack together to form solids, which in turn affects the density and other properties of the material. Knowing what determines the size of an atom helps us understand and predict the behavior of different materials.
The size of an atom is primarily determined by the volume of space occupied by its electrons. The nucleus is too small to significantly affect the overall size. Thus, the chosen answer is (B).
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