B

Band of Stability

N/Z ratio: ~1 (light nuclei) to ~1.5 (heavy nuclei)
Quick Reference
Formula / NotationN/Z ratio: ~1 (light nuclei) to ~1.5 (heavy nuclei)
Also Known AsBelt of stability; stability band; N-Z stability plot; valley of stability (in 3D representation)

What is Band of Stability?

The band of stability (also called the belt of stability) is the region on a plot of number of neutrons (N) vs. number of protons (Z) where stable nuclei are found. Nuclides outside this band are radioactive and decay by various modes (alpha decay, beta decay, positron emission) to reach the stable band. For light elements, N ≈ Z; for heavier elements, N > Z.

Formula & Notation

N/Z ratio: ~1 (light nuclei) to ~1.5 (heavy nuclei)

Other Names / Synonyms: Belt of stability; stability band; N-Z stability plot; valley of stability (in 3D representation)

Properties & Characteristics

Stable nuclei lie within narrow N vs. Z band; for Z < 20: N/Z ≈ 1; for Z > 20: N/Z increases up to ~1.5; nuclei above band (too many neutrons): β⁻ decay; nuclei below band (too many protons): β⁺ emission or electron capture; all elements with Z > 83 are radioactive

Uses & Applications

Nuclear physics and radioactive decay prediction; nuclear medicine (selecting suitable radioactive isotopes for diagnostics and therapy); nuclear reactor fuel selection; understanding natural radioactive decay chains

Safety Information

No hazard from the concept. Nuclides outside the stability band are radioactive and must be handled with appropriate radiation protection.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Band of Stability
Formula N/Z ratio: ~1 (light nuclei) to ~1.5 (heavy nuclei)
Synonyms Belt of stability; stability band; N-Z stability plot; valley of stability (in 3D representation)

Frequently Asked Questions

The band of stability (also called the belt of stability) is the region on a plot of number of neutrons (N) vs. number of protons (Z) where stable nuclei are found. Nuclides outside this band are radioactive and decay by various modes (alpha decay, beta decay, positron emission) to reach the stable band. For light elements, N ≈ Z; for heavier elements, N > Z.

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