• What's a mole? Just like a dozen means 12, a mole refers to a specific number of something.
• Number of things in a mole: 6.02214076 × 10²³ (That's HUGE!)
• This super specific number is called the Avogadro number and is abbreviated as NA.

Did you know? 🤔 Just like you’d say “3 dozen cookies”, you can say “3 mol of electrons”, which would mean you have 3 × 6.02214076 × 10²³ electrons! That’s a LOT of cookies... I mean, electrons.

• 0.5 mol of water has:
  • 6.02214076 × 10²³ hydrogen atoms.
  • 3.01107038 × 10²³ oxygen atoms.
  • Total atoms: About 10²⁴ atoms.
• Makes you think twice before drinking that half-glass of water, right? 😜

• Example: Nitrogen gas (N2) is made of two nitrogen atoms.
  • One mole of nitrogen contains - 12.044 × 10²³ atoms.
  • Mass of one mole of nitrogen atoms = 14.01g.
  • So, 2 atoms (or one N2 molecule) weigh 28.02g.

Old School Fact: Before 2019, the mole was defined by the amount of substance in 12g of carbon-12. But, science evolves! This definition was updated to improve scientific measurements.