Positively-charged particles consisting of two protons and two neutrons emitted by radioactive materials are A) beta particles. B) gamma particles. C) alpha particles. D) positron particles

C. Alpha particles.

Explanation:

An alpha particle is a radioactive particle emitted from a radioactive source. It is made up of two protons and two neutrons. It is a helium nucleus: that is a helium atom without electrons.

Mass number = 4

= number of proton + number of neutrons

= 2 + 2

dec 23, 2016 - a load of bricks weighing 680 n a distance of 10 m across a parking lot. if if the worker pushes the cart with a constant force of 209 n, what work= force x distance = 220 n x 10 m = 2200 n.m = 2200 j i don't know where the person got it from, but the initial part, work= force x distance me.