Problem 19 - Chemistry: The Central Science

Question

(a) Give the names and chemical symbols for the three isotopes of hydrogen. (b) List the isotopes in order of decreasing natural abundance. (c) Which hydrogen isotope is radioactive? (d) Write the nuclear equation for the radioactive decay of this isotope.

Step-by-Step Solution

Answer

The three isotopes of hydrogen are: 1. Protium (\(^1H\)): most abundant with 99.98% natural abundance, 2. Deuterium (\(^2H\)): 0.015% natural abundance, and 3. Tritium (\(^3H\)): least abundant and radioactive. The nuclear equation for Tritium's radioactive decay is: \(^3H \rightarrow ^3He + e^- + \bar{\nu}_e\).

Step 1: Provide the names and chemical symbols of hydrogen isotopes

There are three isotopes of hydrogen, which are: 1. Protium (\( ^1H \)): It has one proton and no neutrons. 2. Deuterium (\( ^2H \)): It has one proton and one neutron. 3. Tritium (\( ^3H \)): It has one proton and two neutrons.

Step 2: List the isotopes in order of decreasing natural abundance

The isotopes of hydrogen can be listed in order of decreasing natural abundance as follows: 1. Protium (\( ^1H \)): It is the most abundant isotope, with around 99.98% of natural abundance. 2. Deuterium (\( ^2H \)): It is less abundant than Protium, with around 0.015% of natural abundance. 3. Tritium (\( ^3H \)): It is the least abundant isotope, as it is only found in trace amounts. Its natural abundance is extremely low, around 10^-18 %.

Step 3: Identify the radioactive isotope of hydrogen

Tritium (\( ^3H \)) is the only radioactive isotope of hydrogen.

Step 4: Write the nuclear equation for the radioactive decay of the radioactive isotope

Tritium (\( ^3H \)) undergoes beta decay, in which it transforms one of its neutrons into a proton and emits an electron (beta particle) and an antineutrino. The nuclear equation for the radioactive decay of Tritium can be written as follows: \( ^3H \rightarrow ^3He + e^- + \bar{\nu}_e \) Here, \( ^3H \) is the tritium nucleus, \( ^3He \) is the helium-3 nucleus, \( e^- \) is the emitted electron (beta particle), and \( \bar{\nu}_e \) is the emitted antineutrino.