How are atoms weighed



How are atoms weighed

In: Chemistry

On a scale?

It’s typically the case that you collect a specific number of atoms, perhaps a mol of them, and weigh the group. Then division can get you the weight of each one.

You take an atom, rip an electron off of it, and launch it past a magnet. The amount it curves as it passes the magnet depends on its speed, the number of electrons ripped off, the strength of the magnet, and the mass of the atom. By fixing everything else, the mass of the atom can be calculated based on the curvature.

You can’t weigh a singular atom, you get a mol value which is 6.022*10^23 of a particular amount of substance. Then you divide that number (Avogadro’s number) by your molar mass of the substance in grams (from the periodic table) to get the weight of how much of whatever you have.

Here’s an example
1 atom / (6.022*10^23 atoms) * 1 mol / 1 mol * (196.97 g) = 3.27*10^24 g

12g C = 1 mol = 6.022*10^-23