Atomic structure：練習題

Which of the following correctly describes the position of the sub-atomic particles within an atom?

An element G has two naturally occurring isotopes: \( ^{69}\text{G} \) and \( ^{71}\text{G} \). The relative abundance of \( ^{69}\text{G} \) is 60% and the relative abundance of \( ^{71}\text{G} \) is 40%.

What is the relative atomic mass (\( A_r \)) of element G?

Element X has an Atomic Number of 20. It exists naturally as two primary isotopes, X-40 (mass 40.0) and X-42 (mass 42.0). The Relative Atomic Mass (\(A_r\)) of naturally occurring Element X is 40.08.

Calculate the percentage abundance of the heavier isotope (X-42), and subsequently determine the total number of electrons present in a stable ion of Element X, \(\text{X}^{2+}\).

In the structure of an atom, where are the protons and neutrons located?

The atomic number of phosphorus is 15. A specific isotope of phosphorus is represented as \( ^{32}\text{P} \). How many protons and neutrons are present in the nucleus of one atom of this isotope?

State the location and the approximate relative mass (to the nearest whole number) of the electron within a neutral atom.

An atom of Bromine-81 ( \(^{81}_{35}\text{Br}\) ) is neutral. Determine the number of protons, neutrons, and electrons present in this atom.

Naturally occurring Argon is comprised mainly of three isotopes: Argon-36, Argon-38, and Argon-40. If the measured Relative Atomic Mass (\(A_r\)) of Argon is 39.95, deduce which isotope has the highest natural abundance and justify your answer.

The sulfide ion, \(\text{S}^{2-}\), is formed when a sulfur atom gains electrons. The sulfur atom has an atomic number of 16 and a mass number of 32.

a) Determine the number of protons, neutrons, and electrons in the neutral sulfur atom, \(^{32}_{16}\text{S}\).

b) Determine the number of electrons in the sulfide ion, \(\text{S}^{2-}\).

c) Write the electronic configuration for the sulfide ion, \(\text{S}^{2-}\).

Element T has an atomic number of 17. It occurs naturally as two isotopes: T-35 and T-37.

a) Calculate the number of neutrons in an atom of the heavier isotope, T-37.

b) A student is asked to determine the number of electrons in the T-35 atom and the T-37 atom. Explain how the number of electrons compares in these two neutral isotopes.

c) Deduce the electronic configuration of a neutral T atom.