A Foray Into Grade 9 and 10 Science MATTER A Foray Into Grade 9 and 10 Science

Classification of Matter

Matter Anything that has mass and takes up space. All matter has properties that can be studied by observation Matter is made up of ATOMS Matter can be divided into Pure Substances and Mixtures

Pure Substances Cannot be separated into two or more substances by physical or mechanical means It has uniform composition throughout the whole sample Its properties are constant throughout the whole sample It has constant chemical composition

Pure Substances There are two types of pure substances: ELEMENT: A substance that cannot be broken down by chemical means. COMPOUND: A substance formed by the reaction of two or more chemical elements. The elements in a compound are present in fixed ratios.

Mixtures Composed of two or more substances, but each keeps its original properties. There are two kinds of mixtures: Homogenous and Heterogeneous

Homogenous Mixtures A mixture which has uniform composition and properties throughout. EXAMPLE: a Kool-Aid stirred into a glass of water will form a homogeneous mixture

Solutions Mixture of a solid and a liquid where the solid never settles out SOLUTE: the solid SOLVENT: the liquid EXAMPLE: Again…Kool-Aid

Heterogeneous Mixtures A mixture that does not have uniform composition and properties throughout EXAMPLE: this lovely bowl of soup.

Heterogeneous Mixtures There are three types of heterogeneous mixtures, Mechanical Mixtures, Suspensions and Colloids

Mechanical Mixtures Mixtures whose components can be separated by mechanical means

Suspensions A heterogeneous mixture in which solute-like particles settle out of solvent-like phase some time after their introduction

Colloids A heterogeneous mixture in which solute-like particles do not settle out. Milk is a colloid because the fat globules aren't completely dissolved in the fluid of the milk

Properties of Matter There are two properties of matter: PHYSICAL: Characteristics of a substance that help to identify it CHEMICAL: How does a substance react when changed into a new substance

Physical Properties STATE: gas, liquid or solid COLOUR SOLUBILITY: ability of a solute to dissolve in a solvent MALLEABILITY: ability of a solid to be bent VISCOSITY: how easily a liquid flows

Physical Properties FREEZING POINT MELTING POINT ELECTRICAL CONDUCTIVITY TEXTURE: rough, smooth or soft HARDNESS DENSITY: how compact a substance is

Chemical Properties COMBUSTIBILIY: will it burn or is it non-flammable REACTION WITH ACID: will it bubble and disappear or will it do nothing

Chemical Change? How do you know if a new substance is formed? Change in colour. Gas production. (e.g. bubbles) Solid production (e.g. PRECIPITATE in liquid) Energy production (e.g. light, heat or sound)