That's kind of a ponderous way to describe it, but your 'X' represents
the absolute temperature of the ideal gas.
It's the sound before the lightning because sound travels faster than light.
First you need to work out what mass of 84g of stainless steel is nickel, and because there's 5% you can simply divide by 20, giving 4.2g
For this you can use the equation

The mass, as was worked out previously, is 4.2g
The Mr, which is found on the periodic table, is 28
Moles =

= 0.15mol
1mol = 6.023 x

atoms
So, 0.15mol = 0.15 x 6.023 x

= 9.0345 x

atoms
They go through radioactive decay because when atoms are unstable by going through it they are emitting radiation in natural process and they gain stability by losing energy.