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Combination Reaction

Two or more reactants combine to form a single product.

Combination Reaction Example

$C(s) + O2(g) \rightarrow CO2(g)$

Decomposition Reaction

A single reactant breaks down into two or more simpler products.

Decomposition Reaction Example

$CaCO3(s) \xrightarrow{\Delta} CaO(s) + CO2(g)$

Displacement Reaction

A more reactive element displaces a less reactive element from its compound.

Displacement Reaction Example

$Fe(s) + CuSO4(aq) \rightarrow FeSO4(aq) + Cu(s)$

Double Displacement Reaction

An exchange of ions between the reactants to form new compounds.

Double Displacement Reaction Example

$AgNO3(aq) + NaCl(aq) \rightarrow AgCl(s) + NaNO3(aq)$

Law of Conservation of Mass

Mass can neither be created nor destroyed in a chemical reaction; total mass of products equals total mass of reactants.

Purpose of Paint on Iron

Paint prevents rusting by creating a protective barrier against moisture and oxygen.

Quicklime and Water Reaction

Quicklime ($CaO$) reacts with water to form slaked lime ($Ca(OH)_2$) releasing heat.

Applications of Baking Soda

Used in baking, as an antacid, and in fire extinguishers.

Applications of Washing Soda

Used in glass, soap, paper industries, and as a domestic cleaning agent.

Applications of Bleaching Powder

Used for bleaching in textiles, as an oxidizing agent, and for disinfecting water.

Chlor-alkali Process

Electrolysis of brine produces sodium hydroxide ($NaOH$), chlorine gas ($Cl2$), and hydrogen gas ($H2$).

Ionic Compounds Conducting Electricity

Ionic compounds conduct electricity in molten state due to free-moving ions, not in solid state due to fixed lattice.

Electrolytic Refining of Copper

Process using impure copper anode and pure copper cathode in copper sulphate solution to purify copper.

Roasting

Heating sulfide ores in excess air to convert them into oxides.

Calcination

Heating carbonate ores in absence or limited air to convert them into oxides.

Diamond Properties

Diamond has a rigid 3D tetrahedral structure, making it the hardest known substance.

Graphite Properties

Graphite has hexagonal layers held by weak forces, making it soft and a good conductor of electricity.

Alcohol Functional Group

Identified by the $-OH$ group; Suffix: -ol (e.g., Ethanol).

Carboxylic Acid Functional Group

Identified by the $-COOH$ group; Suffix: -oic acid (e.g., Ethanoic acid).

Aldehyde Functional Group

Identified by the $-CHO$ group; Suffix: -al (e.g., Ethanal).

Modern Periodic Law

Properties of elements are a periodic function of their atomic numbers.

Atomic Size Trend

Decreases across a period and increases down a group.

Valency Trend

Increases from 1 to 4 then decreases to 0 across a period; remains the same down a group.

Metallic Character Trend

Decreases across a period and increases down a group.

Atomic Radius Decrease

Decreases across a period due to increasing nuclear charge pulling electrons closer.

Newton's Universal Law of Gravitation

Every object attracts every other with a force proportional to the product of their masses and inversely proportional to the distance squared.

Mass Definition

Amount of matter in an object.

Weight Definition

Force of gravity acting on an object.

Mass vs. Weight

Mass remains constant; weight changes with gravity.

Weight Formula

$W = m \times g$.

Power of a Lens

Measure of convergence/divergence of light rays; reciprocal of focal length ($f$) in meters.

Unit of Power of Lens

Dioptre ($D$).

Acceleration due to Gravity ($g$)

Uniform acceleration due to Earth's gravitational pull; approximately $9.8 \text{ m/s}^2$.