Tritium is an isotope of which of the following elements?
2023
Tritium is an isotope of which of the following elements?
Answer: D. Hydrogen — ConceptIsotopes are atoms of the same element with the same number of protons but different numbers of neutrons, so they have different mass numbers. An…
- A.
Helium
- B.
Carbon
- C.
Titanium
- D.
Hydrogen
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Correct answer: D
Concept
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons, so they have different mass numbers.
An isotope remains an isotope of the element identified by its atomic number, which equals its proton count.
Application
Tritium is hydrogen-3. Its nucleus has one proton and two neutrons, giving it mass number 3. Because one proton means atomic number 1, the element is hydrogen.
Contrast
Helium nuclei have 2 protons, so helium isotopes belong to atomic number 2.
Carbon nuclei have 6 protons, so carbon isotopes belong to atomic number 6.
Titanium nuclei have 22 protons, so titanium isotopes belong to atomic number 22.
Cross-check
The notation hydrogen-3 preserves hydrogen's atomic number 1 while changing only the neutron count. Therefore, tritium is an isotope of hydrogen.