They have less or more neutrons. Isotopes have same number of protons but different number of neutrons.
Answer:
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles
I would suggest convection !!!
In order to calculate the average value of cells B2:B6, you need to enter the formula on cell B7, On the Home tab, in the Editing group, click the Sum (AutoSum) button arrow and select Average . (and press Enter). The answer in this question is On the Home tab, in the Editing group, click the Sum (AutoSum) button arrow and select Average . (and press Enter).
