Using the rules for significant figures, what do you get when you subtract 15.54 from 508.9538?

493.41

Explanation: We have been asked to subtract 15.54 from 508.9538.

Thus 508.9538 - 15.54 = 493.4138

By using the rules for significant figures for subtraction, round the answer to the least number of places to the decimal point of any number in the problem. As one number contains 2 decimal places and the other number contains 4 decimal places.

Thus the answer should have 2 decimal places. Thus the answer should be 493.41.

he . if i may ask what i your question exactly?

explanation:

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.