Unit B Study Guide

What do the WHMIS symbol for Flammable indicate?

Indicates materials that easily ignite and burn.

Corrosive

Substances that cause burns or destroy materials, such as acids.

Toxic (Acute)

Substances harmful or fatal even in small doses.

What did Democritus propose about matter?

He proposed the idea of indivisible particles called 'atoms'.

Dalton's Atomic Theory

Atoms are indivisible and unique to each element.

What model did Thomson propose?

The 'plum pudding' model, which included electrons.

What did Rutherford's gold foil experiment prove?

The existence of a dense nucleus.

Bohr Model of the Atom

Proposes that electrons orbit the nucleus in fixed energy levels.

Pure Substances

Substances that cannot be broken down further, including elements and compounds.

Element

A substance that cannot be broken down into simpler substances.

Compound

A substance composed of two or more elements that are chemically bonded.

Mechanical Mixture

A mixture where components remain visibly distinct.

Solution

A homogeneous mixture where one substance is fully dissolved in another.

What are colloids?

Mixtures where fine particles are evenly distributed and do not settle.

Chemical Change

A change that creates new substances with new properties.

Physical Change

A change that alters the form of a substance but not its composition.

What are noble gases?

Stable, non-reactive gases found in Group 18 of the periodic table.

Families in Periodic Table

Groups/columns such as Halogens and Noble Gases.

What do metals typically exhibit?

High conductivity and malleability.

Atomic Structure

Composed of protons, neutrons, and electrons with specific charges.

Protons

Positively charged particles found in the nucleus.

Neutrons

Neutral particles found in the nucleus.

Electrons

Negatively charged particles located in electron orbits.

H₂O

Water molecule, consisting of two hydrogen atoms covalently bonded to one oxygen atom.

Ionic Compounds

Composed of a metal and a nonmetal.

Molecular Compounds

Composed of nonmetals only.

What are polyatomic ions?

Ions that consist of multiple atoms, such as carbonate or sulfate.

H₂SO₄

Chemical formula for sulfuric acid, consisting of 2 hydrogen, 1 sulfur, and 4 oxygen.

Endothermic Reaction

A reaction that absorbs heat.

Exothermic Reaction

A reaction that releases heat.

Combustion

The burning of a substance in oxygen to produce energy.

Corrosion

The slow oxidation process, such as rust formation.

Conservation of Mass

The principle that states that mass is conserved in a chemical reaction.

What factors affect the rate of chemical reactions?

Catalysts, temperature, surface area, and concentration.

What is the general format for writing chemical reactions?

Reactant + Reactant → Product.