What happens to particle motion when the heat is added? how do you suppose this would affect the rate at which a chemical change takes place?

Explanation:

When heat is added to an object it's internal energy increase. What is meant by internal energy is the kinetic energy and potential energy of the particles in an object. Potential energy of particles is according to the structure of particle arrangement within the object.

As kinetic energy increases the motion of the particles within the molecule increases therefore the speed of the particles inside the object increases, so the probability of atoms interacting with each other to produce new substance also increases. So the rate of chemical reaction increases.

Actually what we feel as heat is a measurement of the amount of kinetic energy the particles in the object have.

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.