# Physics - Moles

> Source: https://ollybritton.com/notes/a-level/physics/topics/moles/ · Updated: 2021-11-08 · Tags: school, physics, year-2

## Flashcards
##### What does Avagadro's constant represent??
The number of atoms in $12$ grams of Carbon-12.

##### What is one mole of a substance??
An amount in which the number of atoms/molecules is equal to Avogadro's constant.

##### What is the molar mass of a substance??
The mass per mole of a substance.

##### How do you find the mass of one atoms from its mass number/nucleon number??
Divide the mass number by Avogadro's constant.

##### What is a nucleon??
A proton or a neutron.

##### What is the mass number??
The number of protons or neutrons in the atom.

##### $$^{35}_{17} Cl$$ Which number is the mass/nucleon number?/
$$
35
$$

##### How can you calculate the number of particles from the number of moles of a substance??
$$
\text{number of moles} \times \text{Avagadro's constant}
$$

##### What is the molecular mass of a substance??
The mass of one molecule/atom of that substance.

##### What is the value of Avogadro's constant??
$$
6.02 \times 10^{23}
$$

##### How many atoms are there in one mole of $^{12}C$??
$$
6.02 \times 10^{23}
$$

##### How many atoms are there in one mole of $^{35}Cl$??
$$
6.02 \times 10^{23}
$$

##### How many grams are there in one mole of $^{12}C$??
$$
12g
$$

##### How many grams are there in one mole of $^{35}C$??
$$
35g
$$
##### What is $N$ (the number of atoms/molecules) in terms of $n$ (the number of moles) and $N_a$ (Avogadro's constant)??
$$
N = n \times N_A
$$

##### What is $m$ (the mass of a substance) in terms of $n$ (the number of moles) and $M$ (the molar mass)??
$$
m = n \times M
$$

---
Olly Britton — https://ollybritton.com. Machine-readable index: https://ollybritton.com/llms.txt