To **predict which molecule **is most likely to **undergo beta decay**

Recall that the ** stability of an isotope** depends on the ratio of neutrons to protons (N/Z). This means for stable isotopes with:

• **Z ≤ 20**; the N/Z ratio should be **equal to 1.0**

• **20 < Z ≤ 40**; the N/Z ratio should be **equal to 1.25**

• **40 < Z ≤ 80**; the N/Z ratio should be **equal to 1.50**

• **Z < 83**; the stable nuclide **does not exist**

This means for isotopes:

• **beta decay ( ^{0}_{–1}β) → **if

**a) Si-22**

**Mass number = 22****Atomic number = 14****→****# of protons, Z = 14****N = Mass number - Z****N = 22 -14 =**

$\frac{\mathbf{N}}{\mathbf{Z}}\mathbf{=}\frac{\mathbf{8}}{\mathbf{14}}\mathbf{=}{\mathbf{0}}{\mathbf{.}}{\mathbf{57}}$

Which nuclide is most likely to undergo beta decay?

a) Si-22

b) Rb-91

c) Ar-35

d) Co-52

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Band of Stability concept. You can view video lessons to learn Band of Stability. Or if you need more Band of Stability practice, you can also practice Band of Stability practice problems.

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