Show Menu

Yr 9 Chemistry Notes Cheat Sheet (DRAFT) by

Yr 9 Chemistry Notes

This is a draft cheat sheet. It is a work in progress and is not finished yet.


Everything is made up of matter.
Matter is made up of atoms.

Classi­fic­ation of matter

Periodic Table

Table of all known elements arranged from left to right and top to bottom in order of increasing atomic number, or the number of protons.
Columns: Refer to groups of the table
Rows: Refer to as periods or the families of the table

Structure of the Periodic Table

Elem­ents, Compounds, and Mixtures

Element: A pure substance made from one type of atom.
E.g. Sodium Formula: Na
Compounds: Made from more than one type of atom bonded together.
E.g. Sodium
Formula: NaOH
Mixtures: Made of substances which are not chemically bonded and can be separated.
E.g. Salt Water Formula: NaCl

Inform­ation on the Periodic Table

Atomic Number
Atomic Mass
Number of Protons
Number of Neutrons
Number of Electrons


Atoms consist of three subatomic particles protons, Neutrons, and Electrons.

Atomic Structure

Electron Config­ura­tions

The shells are numbered beginning with the shell closest to the nucleus and increasing in number farther away from the nucleus.

Electron Shell Diagrams

Electron shells are numbered from the shell closest to the nucleus outwards.


Particles orbiting the nucleus
of the atom
Negatively charged
No mass
Electrons orbit the nucleus in electron shells.
Maximum Number of electrons:
The first electron shell holds
2 atoms
The second electron shell holds
8 atoms
The third electron shell holds
8 atoms

The Law of Conser­vation of Mass

The mass in an isolated system can neither be created nor be destroyed but can be transf­ormed from one form to another

Counting Atoms

Acid-Metal Reactions

Metals react with acids to form a salt and hydrogen.
Identi­fic­ation: Pop Test
The presence of hydrogen gas can be determined by placing a lit splint near the test tube.
Hydrogen reacts causing a squeaky pop sound.

Acid + Metal General Formula

Exothermic and Endoth­ermic Reactions

All chemical reactions either use energy or release energy.
Reactions that require energy are endoth­ermic.
Reactions that release energy are exothermic.

Properties of Acids & Bases

pH between 0-7
pH between 7-14
Taste sour
Taste bitter
Neutra­lizes bases
Neutra­lizes acids
Reacts with metals to
form hydrogen gas

pH Scale

pH Scale

pH 0 - 6
pH 7
pH 8-14
Alkaline (Basic)


Colour in Acid
Colour at neutral
Colour in Base
Universal Indicator (UI)
Blue Litmus Paper

General Word Equations

Acid + Base → Salt + water
Acid + Metal → Salt + Hydrogen gas
Acid + Carbonate → salt + water + carbon dioxide
Fuel + Oxygen → Carbon dioxide + water
Oxygen + iron + water → iron oxide (rust)

General Formula for Acid-Base Reactions

Acid + Base Reactions

Hydroxide ions (OH-) from the base, attach to hydroxide (H+) ions from the acid, producing water.
The remaining atoms form a salt.
Neutra­lis­ation reaction using universal indicator to indicate pH of 7

Naming Salts

The first part of the name comes from the base, the second from the acid.
Sodium hydroxide
Hydrochloric acid
Sodium chloride
Magnesium oxide
Nitric acid
Magnesium Nitrate
Sodium hydroxide
Sulfuric acid
Sodium sulfate

Acid-C­arb­onate Reactions

Acids react with metal carbonates to form a salt, water and carbon dioxide.
Identi­fic­ation: Limewater Test
Limewater can be used to indicate CO2 production turning milky white when the gas is present.

Acid + Carbonate General Equation