Analyze the definition of light-year. Why is it in space we use light-year to measure distance? *

Because the distance is too far to count with any other way

Explanation:

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

→

it would be d. henry moseley

hope this !

and sorry if i'm late. have a good rest of your day! : d