Express each of the following numbers in standard scientific notation:
0.2953
2953000
2.953

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

it should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.

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.