revision p4

revision p4

1. Alpha particles are a form of nuclear radiation with a large positive charge.

   • two atoms of the same element with the same number of protons but a difrent number of nuetrons are called iysotope

2. some substance are classed ass "radioactive" which makes them unstable

3. a becquerel is one decay per second

4. Alpha - two protons and two nutrons

5. beta - electrons from the nucles

6. gamma -electromagnetic radiation

7. half life is time taken for radioactivity of a specified isotype to fall to half of it original value

8. the atomic number tells us how many protons and electrons an element has.

9. the atomic mass tells us the total number of protons and neutrons an element has

10. the number of protons and the number of electrons in an electrons in an atom are always equal.

11. if an atom loses or gains