Question

3. Carbon -14 underwent radioactive decay and emitted beta particles.

Answer 1

The decay reaction of Carbon-14 which releases Beta particles, resulting in the element Nitrogen-14

Further explanation

Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,  

• alpha α particles ₂He⁴
• beta β ₋₁e⁰ particles
• gamma particles ₀γ⁰
• positron particles ₁e⁰
• neutron ₀n¹

Carbon-14 emits beta β ₋₁e⁰ particles , so the atomic number increases by 1, the mass number remains the same

Reaction

$\tt \large{\boxed{\bold{_6^{14}C\rightarrow _7^{14}N+_{-1}^0e}}$