If an atom of thorium-234 were to undergo beta emission twice, which atom would result?

rn-226

u-234

th-230

u-238

The answer to your question is  U-234

Explanation:

Data

Thorium-234

beta emission twice

Definition

Beta emission is when a beta particle (electron) is emitted from an atomic nucleus.

First beta emission

                                            ²³⁴₉₀Th   ⇒    ²³⁴₉₁Pa + e⁻

Second beta emission

                                            ²³⁴₉₁ Pa   ⇒  ²³⁴₉₂U  + e⁻

The atom will be Uranium-324

U-234

Explanation: no matter how much of beta decay, the mass number of the resulting element is unchanged

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation: