An atom of the element of atomic number 84 and mass number 199 emits an alpha particle. The residual atom?

Question

after this change has an atomic number of _________ and a mass number of ________?

82, 195
84, 203
85, 195
86, 199

Also, can you explain how you got the answer. Thanks.

Answer 1

An alpha particle is 2, 4. So if the base element is 84, 199 then the answer would be the first one. alpha has 2 protons and two neutrons.

Answer 2

A) when an atom emits an alpha he looses 2 protons and 2 neutrons

So atomic number Z which represents the number of protons is decreased by 2 : here 84-2 =82

and The mass number A which represents number of protons +neutrons is dereassed by 4 :here 199-4= 195

the atom polonium 199, yields plumb 195

Answer 3

This Site Might Help You.

RE:
An atom of the element of atomic number 84 and mass number 199 emits an alpha particle. The residual atom?
after this change has an atomic number of _________ and a mass number of ________?

82, 195
84, 203
85, 195
86, 199

Also, can you explain how you got the answer. Thanks.

Answer 4

84 is polonium. alpha is 2He4

84Po199 -2He4=82Pb195

It is a subtraction problem, harder to show on the keyboard. Subtract the atomic numbers and subtract the atomic masses


For beta decay, you add 1 proton or 1 to the number

Answer 5

82,195 is the correct answer ....as see whev an alpha partical is emmited the mass number deduct 4 from the mass num n deduct 2 from atomic num..........in case of emittion of beta partical add 1 to atomic num n mass num will be same trust me the is absolutle correct