To write 258/300 as a decimal you have to divide numerator by the denominator of the fraction. We divide now 258 by 300 what we write down as 258/300 and we get 0.86
And finally we have: 258/300 as a decimal equals <span>0.86</span>
The existence of isotopes contradicts part of Dalton's original atomic theory because he said all atoms of a given element are identical have the same mass size and chemical properties.