The nucleus of an atom emits a particle. the particle is equal in size to a helium nucleus. what is this particle? a) an alpha particle
b) a beta particle
c) a newton
d) a gamma ray

A) Alpha particle

Explanation:

An alpha particle is identical to a helium nucleus, since consists of 2 protons and 2 neutrons.

The charge of an alpha particle is +2e and its mass is 4 a.m.u.

Alpha particles are produced in alpha decays. Alpha decays occur when a nucleus emits an alpha particle: as a result, the atomic number of the nucleus decreases by 2 units, while its mass number decays by 4 units.

The equation that represents an alpha decay is

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s