Language of Chemistry

Define homogeneous mixtures.

Homogeneous mixtures are uniform throughout

Define heterogeneous mixtures.

heterogeneous mixtures do not have the same composition throughout.

What are physical properties?

Properties that can be observed without changing a substance into another substance, e.g., boiling point, density.

What are chemical properties?

Properties observed when a substance is changed into another substance, e.g., flammability, reactivity.

What are intensive properties?

Properties that are independent of the amount of the substance, e.g., density, boiling point.

What are extensive properties?

Properties that depend on the amount of the substance, e.g., mass, volume.

What are physical changes?

Changes that do not alter the composition of a substance, e.g., melting, boiling.

What are chemical changes?

Changes that result in the formation of new substances, e.g., combustion, oxidation.

What is the Aufbau principle?

Electrons fill orbitals starting from the lowest energy level to the highest.

What is Hund's rule?

Electrons will occupy degenerate orbitals singly before pairing up.

What is the Pauli exclusion principle?

No more than two electrons can occupy a single orbital, and they must have opposite spins.

What is the octet rule?

Atoms tend to gain, lose, or share electrons to achieve a full valence shell of 8 electrons.

What is a mole?

A unit representing 6.022 x 10²³ particles

How is molarity (M) calculated?

Molarity = moles of solute / volume of solution in liters.

What is empirical formula?

The simplest ratio of atoms in a compound.

What is molecular formula?

The actual number of each type of atom in a molecule.