Question

Which answer choice best explains why atoms of carbon-14 (C-14) are unstable?
Atoms of C-14 have too many negatively charged electrons and too few positively charged protons.
Atoms of C-14 have too many positively charged protons and too few negatively charged electrons.
There are 2 more protons than neutrons in the nucleus.
There are 2 more neutrons than protons in the nucleus.

Answer 1

There are 2 more neutrons than protons in the nucleus.

Carbon-14 has 6 protons and 8 neutrons, giving a neutron-rich nucleus that is unstable and undergoes beta decay (a neutron converts to a proton, emitting an electron) to become stable nitrogen-14.