Look at the graph below. Number of Half-lives
20 3.0 4.0
10
5.0
100
75
60
Со
27
Grams of Coromaining
25
00
00
5.27
10.54
15 81
21.08
26.35
Time in years
How many grams of cobalt-60 will remain after three half-lives?
O A. 1.25 g
O
B. 2.5 g
O C. 180 g
O D. 39

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.

ice to water 1 water to vapour 2 latent heat

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop

massxgravity x heght=weightxheight= pe

4900=490xh

h=10