Complete these sentences by matching the phrases below. Scientists
extrapolate
backwards in
time to derive:
?
the Doppler effect.
The extremely
low temperature
of outer space
can be explained
as:
2
cosmic microwave
background radiation.
Scientists smash
together tiny bits
of matter using:
particle accelerators.

a. they are both space stations

happy to

pls mark as brainliest.

the temperature of the gas, in k, not celsius.

answer///carbon;

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.