Mrs. Roberts' class was designing science experiments. Carl and his partner decided to use the outdoor classroom as their laboratory. Since there was a bird feeder in the outdoor classroom, they decided to design an experiment about the feeding habits of birds in their area. Which question would be MOST appropriate to guide the scientific investigation?

A) What do birds eat?
B) What type of seeds do birds prefer?
C) Which seeds do our feeder birds prefer?
D) Which types of seeds do our feeder birds eat?

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

so easy. just google the electromagnetic waves and it’ll pop up.