25% of chlorine atoms are 37 Cl and 75% are 35 Cl. The weighted mean mass of chlorine is 35.5. The relative atomic mass of an element is a weighted mean mass of the isotopes of an element compared ...

Accompanying Lesson Plan: Lesson 3.2: Finding Volume—The Water Displacement Method The chart shows that atomic size and mass for the first 20 elements in the periodic table. The size of the atoms and ...

Nuclear fission – the physical process by which very large atoms like uranium split into pairs of smaller atoms – is what makes nuclear bombs and nuclear power plants possible. But for many years, ...