3 should be B hop this helps
Correct answer is B.
It has α-particle , which is a nuclei of He,
also you need to check charge before and after the reaction
Charge is written down
92=90+2, true
also you need to check mass before and after
238=234+4, true
Answer:
d) chlorine
Explanation:
because it favors gaining electrons than losing , its a nonmetal
Answer:
21
Explanation:
Formula;
Mass number = number of protons + number of neutrons
= 9 + 12
= 21