Me feel in the blanks giving 30 points 4) properties can only be observed when a substance changes into another substance. 5) properties such as color and shape are easy to observe. 6) in a chemical change a substance forms. 7) cooking or baking food results in a change. 8) a melting ice cube is a change. 9) iron rusting is an example of a change. 10) water boiling on the stove is an example of a change

4:chemical properties can only be observed when a substance changes into another substance.

5: physical properties such as color and shape are easy to observe

6: in a chemical change an altered substance forms

7: cooking or baking food will result in a chemical change

8: a melting ice cube is a physical change

9: the rusting of iron is a chemical change

10: water boiling is a scientific physical change

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.

your answer is, orbit around the nucleus