Question

question 19 (1 point)
an α particle is also known as
an electron.
a positron.
a helium nucleus.
a photon.

Explanation:

An alpha particle (α particle) consists of 2 protons and 2 neutrons, which is the same as the nucleus of a helium atom (since a helium atom has 2 protons and 2 neutrons in its nucleus, and the electrons are much lighter and not part of the alpha particle's structure). An electron is a negatively charged subatomic particle, a positron is a positive electron (antiparticle of electron), and a photon is a quantum of electromagnetic radiation. So an α particle is a helium nucleus.

Answer:

C. a helium nucleus.