Please help on my chemistry/ physics question!?

Question

When thorium (A=90) emits a beta particle, the resulting nucleus has an atomic number
a. 88
b. 89
c. 90
d. 92
e. none of these

Answer 1

e. A beta particle is an electron. A neutron has changed into an electron (emitted) and leaves one more proton in the nucleus. Thus the charge in the nucleus goes UP, by ONE. A=91.

Reference was not an easy find...but the logic to the problem is not hard.

Answer 2

the answer, i think, is c because the atomic number is dependent on protons, but a beta particle contains no protons, it is only an electron. so the charge on the thorium would differ but the atomic number would still be 90. i think...

Answer 3

Shalom! That answer would be "e". The thorium would gain a proton with beta emissions and become Protactinium 91 +ion.
Trust me, I'm a nuclear phyicist.

Answer 4

what is a beta particle....that should be easy to find on web. should be easy after you have determined that