Chemistry
marisol123
2015-11-03 21:09:45
What change in mass number occurs when a radioactive atom emits an alpha particle?
ANSWERS
ntbaker98
2015-11-04 00:07:09

The alpha particle is the helium nucleus. The mass of helium nucleus (⁴₂He) is 4u. The mass of radioactive atom decreases by 4u. Look at the reaction below: ²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn

ADD ANSWER