Isotopes

Definition

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons in their nuclei. They have nearly identical chemical properties but differ in atomic mass and physical properties.

5 Must Know Facts For Your Next Test

1. Isotopes of an element have the same number of protons (atomic number) but different numbers of neutrons.
2. The atomic mass of an element listed on the periodic table is the weighted average of all its naturally occurring isotopes.
3. Some isotopes are stable, while others are radioactive and decay over time, emitting radiation.
4. Isotopic composition can help astronomers determine the age and origin of celestial objects by analyzing spectral lines.
5. In astronomy, isotopic analysis is crucial for understanding nucleosynthesis processes in stars.

Review Questions

• What differentiates one isotope from another within the same element?
• How do isotopes affect the atomic mass listed for an element on the periodic table?
• Why are isotopes significant in the study of celestial objects and their origins?

Related terms

Proton:

A subatomic particle found in the nucleus of an atom with a positive electric charge.

Neutron:

A subatomic particle found in the nucleus of an atom with no electric charge.

Spectral Lines:

Dark or bright lines in a spectrum caused by absorption or emission at specific wavelengths, used to identify elements and isotopes.