At stp, a 1-liter sample of ne(g) and a 1-liter sample of kr(g) have the same (1) mass (2) density (3) number of atoms (4) number of electrons

The answer you are looking for is (3) number of atoms.

Avogadro's law dictates this to be the case. This law states that when you have equal volumes of gases (1 L) at the same temperature and pressures (in this case STP), each vessel will have the same number of molecules.

The law states the same number of molecules, however, neon and krypton are noble gases which are found as single atoms rather than an entire molecule. So the law still applies to these gases.

The reaction will shift to the right

Answer : option a) 84explanation :

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.