Aspaceship orbiting earth flies to the moon. how is the gravitational force pulling on the spaceship related to the distance that the spaceship is from the earth? as the distance from the earth decreases, the gravitational pull on the spaceship would decrease. the gravitational pull of the earth is constant and therefore the gravitational pull on would not change. there is no gravity on the moon and therefore only the earth will exert gravitational force on the spaceship. as the distance from the earth increases, the gravitational pull on the spaceship would decrease.

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.

there are no correct statementd on the list of choices you provided.