Final answer:
The average mass of one potassium atom is 6.49×10^-23 grams, computed by dividing the molar mass of potassium (39.10 g/mol) by Avogadro's number (6.022×10^23 atoms/mol).
This tiny mass is impractical to weigh on any balance due to the minuscule weight of individual atoms.
Step-by-step explanation:
To find the average mass of one potassium (K) atom in grams, we can use the atomic mass unit (amu) and the concept of molar mass. The atomic mass of potassium is 39.10 amu, which is equivalent to its molar mass of 39.10 g/mol. An atom's mass is extremely small, and a quantity called the unified atomic mass unit (u) helps us quantify it, where 1 u = 1.6605×10-27 kg.
To calculate the average mass of one potassium atom, we convert amu to grams. A single mole of potassium atoms weighs 39.10 grams and contains Avogadro's number of atoms (approximately 6.022×1023 atoms).
The average mass of a potassium atom is therefore calculated by dividing the molar mass by Avogadro's number:
Average mass of one K atom = Molar mass / Avogadro's number = 39.10 g/mol ÷ 6.022×1023 atoms/mol = 6.49×10-23 grams/atom.
This tiny mass is impractical to weigh on any balance due to the minuscule weight of individual atoms.