Question

Americium-241 is an alpha emitter used in household smoke detectors and K-40 is a positron emitter used to date rock samples. The daughter nuclides in these two reactions are:

Answer 1

Neptunium - 237 , Argon - 40 .

Step-by-step explanation:

Americium - 241 ⇒ Neptunium - 237 + alpha particles

²⁴¹₉₅Am ⇒ ²³⁷₉₃Np + ⁴₂α

K-40 ⇒ Argon 40 + positron .

⁴⁰₁₉K ⇒ ⁴⁰₂₀Ar + ₁e

Answer 2

Np-237, Ar-40.

Step-by-step explanation:

Alpha particle is positively charged particle having a mass of 4 unit. Hence,when alpha is removed from any isotope it produces a element having mass 4 units less than original isotope that was before emission. Americium 241 isotopes used in the smoke detector which emit an alpha particle to produce neptunium-237.

Potassium-40 emits positron which is having negative charge to lower one proton and increase one neutron number in the particle and in such way it will produce
`^(40)Ar_(18)` not
`^(40)Ca_(20)`