Opposite charges attract! Like charges repel!
This is a kind of electroscope student made in science class to study charges.
Student Procedure:
~Tear off two pieces of tape, each 4 inches (10 cm) long.
~Press each piece firmly on the work table leaving one end of each tape piece sticking up as a handle.
~Quickly pull the tapes from the table and stick one piece on the arm of a straw in one film canister, and the other piece on the arm of a straw in the other film canister.
~Move the canisters so the two pieces of tape are face to face, about 6 inches apart.
~Slowly move the canisters closer together.
~Notice that the two tapes repel each other.
Ms. Mann tore off a another piece of tape and pressed the tape firmly on her lab bench. As she was pulling the piece of tape "up" she ripped a second piece of tape from the dispenser.

What would be a logical argument about how the pieces of tape Ms. Mann prepared would behave? Explain.

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.