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
Explanation:
atomic mass
Really...i think it can also be atomic number..
Answer:
the answer is 25.032g check pic for explanation
173.99cm multiply 68.5 x 2.54 always use that number when converting inches to cm