During a camping trip, Ming gathers firewood and arranges it in the pit. She sets it on fire, and the result is a roaring blaze. Which statement best show all the energy transformation that takes place. A. chemical to thermal B. thermal to electromagnetic
C. chemical to thermal and electromagnetic
D. chemical and electromagnetic to thermal

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.

it becomes positively charged by charging it

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s