Atoms, Molecules, and Bonds – Foundations of Chemistry

• The process where the particles mix and spread by bombarding with other particles is known as diffusion.
• The smallest particles that can't be broken in chemical reactions are called atoms.
• When 2 or more atoms join together are called molecules.
• An atom or group of atoms that carries a charge is an ion. 
• Arrangement of a solid in a fixed, regular pattern is known as a lattice.
• The heating curve shows how the temperature of a substance changes as you heat it up.
• Temperatures remain constant while water changes state. These temperatures are its melting and boiling points.
• A cooling curve shows how the temperature of a substance changes as you cool it down.
• When you heat a gas, volume increases, and pressure decreases. When you cool a gas, its volume decreases, and its pressure increases. The lower the mass of its particles, the faster the gas diffuses. The lower the molecular mass, the faster the gas will diffuse.
• A compound is made of atoms of different elements bonded together.
• A mixture contains different elements or compounds that are not bonded together.
• An element is made up of 1 kind of atom.
• The total number of protons and neutrons in the nucleus of an atom is called the nucleon or Mass number.
• Relative Atomic Mass is the average mass of isotopes, compared to 1/12 of the carbon-12 mass.
• Elements with the same number of protons, but a different number of neutrons, are called isotopes.
• A strong electrostatic force of attraction between ions of opposite charge is an ionic bond.
• The force of attraction between the nuclei and the shared pair of electrons is a covalent bond.
• Metallic bonds are electrostatic attractions between the positive metal ions and a sea of delocalised electrons.