4th Year Chemistry Review Topics 2026

Vocabulary flashcards covering states of matter, atomic structure, periodic trends, chemical bonding, crystal structures, equations, and mole calculations for 4th Year Chemistry.

Diffusion

The movement of particles from a region of higher concentration to lower concentration, providing evidence that matter is made of particles.

Osmosis

The movement of water molecules through a semi-permeable membrane, serving as evidence for the particulate nature of matter.

Melting Point

The constant temperature at which a solid changes state into a liquid.

Boiling Point

The constant temperature at which a liquid changes state into a gas throughout the liquid.

Freezing Point

The constant temperature at which a liquid turns into a solid.

Rf Value

A calculated ratio used in chromatography to aid in identifying unknown substances based on distance traveled.

Solubility Curve

A graph depicting how the solubility of a solute in a given solvent changes with temperature.

Atomic Number

The number of protons in the nucleus of an atom.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Atoms of the same element with the same atomic number but different mass numbers, exhibiting identical chemical properties but slightly different physical properties.

Short Periodic Table

The arrangement of the first 20 elements along with their electronic configurations.

Metals (Periodic Table)

Elements belonging to Groups 1 to 3 (excluding Hydrogen and Boron) located to the left of the zig-zag line on the Periodic Table.

Non-metals (Periodic Table)

Elements belonging to Groups 4 to 8 located to the right of the zig-zag line on the Periodic Table.

Dmitri Mendeleev

The chemist credited with being the creator of the first version of the Periodic Table.

Atomic Radius Trend (Group)

The increase in atomic radius of metals going down a group, caused by each consecutive element having one more electron shell than the element directly above it.

Periodic Character Trend

The trend wherein elements become more non-metallic and less metallic in character as you move across a period.

Ionic Bonding

Electrovalent bonding formed by the transfer of valence electrons between metals and non-metals.

Covalent Bonding

Chemical bonding formed by the sharing of electron pairs between non-metal atoms.

Four Types of Crystals

The main solid crystal structures consisting of metallic crystals, ionic crystals, simple molecular crystals, and giant molecular crystals.

Allotropes

Different structural forms of the same element in the same physical state, such as diamond and graphite.

Coefficients

The numbers written in front of chemical formulas when balancing chemical equations.

State Symbols

Symbols added to chemical equations to indicate physical states: $(s)$ for solids, $(l)$ for liquids, $(g)$ for gases, and $(aq)$ for aqueous solutions.

Relative Molecular Mass (RMM)

The sum of the relative atomic masses of all atoms present in a molecular formula.

Molar Mass

The mass of one mole of a substance, equivalent to the RAM or RMM expressed in grams, with units of $g\,mol^{-1}$.

Avogadro's Constant

A constant used in chemical calculations to convert between number of moles and total number of particles.

Empirical Formula

The simplest whole-number ratio of atoms of each element present in a compound.

Molecular Formula

The actual number of atoms of each element present in a molecule of a compound.

Molar Volume of Gases

The volume occupied by one mole of gas under specified conditions, such as room temperature and pressure (r.t.p) or standard temperature and pressure (s.t.p).