# AP Physics 2: 2.2 Probability and Systems

AP Physics 2: 2.2 Probability and Systems. What is the mass number of J?

AP Physics 2 | Probability and Systems |

Science Practice 4 | Using data collection strategies |

### Transcript

earth with the extraterrestrials are in desperate need of you

to thirty three to return to their home planet Having

limited english speaking abilities they don't know the name of

the substance required to make you two thirty three However

they do have following equation this one right there and

mark's neutrons and beta is beta minus decay which is

a type of electron emitting radioactive decay Determining the mass

number of j will tell us what element to search

for So what is the mass number of jay And

here are potential answers Well see that's thing about aliens

they never seem to be prepared There must not be

a space boy scout model but we'll help these little

freaks out notation might make this a little unclear So

clean it up a bit by taking out those betas

and subbing in the notations for electron we see that

electrons don't add anything to the masked number And since

we're dealing with a neutron on the left side of

the equation will no take that too Now we can

write the equation like this mary because there's a little

thing called conservation of mass that we have to deal

with mass number or a on the right side has

evil the mass number on the left side So the

sum of the mass of the starting point here and

less j test equal the sum of the mass of

the ending point You plus e plus gama if the

mass number of the iranians it's two thirty three the

electron and the anti neutrino don't contribute to the mass

number So just looking at the masked number we now

have this equation we saw for a yeah we find

it has a mass Number of two Thirty two Which

means correct answers to see With this solve the aliens

can be on their way Maybe this means mrs frederiksen 00:02:01.112 --> [endTime] can return to her home planet