Exploring the Nature of Matter

What is Matter? Simply put, matter is anything that occupies space and has mass. Simply put, matter is anything that occupies space and has mass.

What is Matter? More specifically, matter is what molecules and atoms are made of. More specifically, matter is what molecules and atoms are made of.

What We Know About Matter – The Particle Theory The Particle Theory of Matter states: The Particle Theory of Matter states: –All matter is made up of very tiny particles. –Each pure substance has its own type of particle. –Particles attract one another. –Particles are always moving. –The higher the temperature the more movement.

Particle Theory and States of Matter There are three states of matter: There are three states of matter: –Solid –Liquid –Gas The Particle Theory can be used to explain how particles behave in each state. The Particle Theory can be used to explain how particles behave in each state.

Other Classifications of Matter Besides solid, liquid and gas matter can classified in other way. Besides solid, liquid and gas matter can classified in other way. Matter can be heterogeneous or homogeneous. Matter can be heterogeneous or homogeneous.

Other Classifications of Matter Matter can also be classified as a mixture or a pure substance. Matter can also be classified as a mixture or a pure substance.

Changes in Matter Matter has properties or characteristics. Matter has properties or characteristics. Water as a solid can support weight. Water as a solid can support weight. Coal is dark in colour. Coal is dark in colour.

Properties in Matter These properties can change. These properties can change. Ice can melt. Ice can melt. Coal can burn. Coal can burn.

Changes in Matter Changes in matter can be classified in two different categories Changes in matter can be classified in two different categories –Physical change –Chemical change

Physical Changes in Matter During a physical change in matter no new substance is formed. During a physical change in matter no new substance is formed. It does not change their chemical nature. It does not change their chemical nature.

Physical Changes in Matter Examples of physical changes: Examples of physical changes: –Melting ice –Carving a baseball bat out of wood –Breaking a glass –Cloud forming in the sky

Chemical Changes in Matter In a chemical change at least one new substance is formed with new properties. In a chemical change at least one new substance is formed with new properties. A chemical change is difficult or impossible to reverse. A chemical change is difficult or impossible to reverse.

Chemical Changes in Matter Examples of chemical changes: Examples of chemical changes: –Burning coal –Metal rusting –Photosynthesis

Time to Read Please open your books to page 156 and… Please open your books to page 156 and…

Properties of Matter: Chemical or Physical? Properties of matter fall under two categories: Properties of matter fall under two categories: –Chemical Properties –Physical Properties What is the difference? What is the difference?

Physical Properties Physical properties of matter are properties that can be observed without forming a new substance: Physical properties of matter are properties that can be observed without forming a new substance: –The colour of an object. –The smell of an object. –The density of an object.

Physical Properties: Qualitative or Quantitative A qualitative measure is one that can be observed but not measured. A qualitative measure is one that can be observed but not measured. –Taste –Malleability –Smell

Physical Properties: Qualitative or Quantitative A quantitative property is one that can me measured numerically. A quantitative property is one that can me measured numerically. –Density –Boiling Temperature –Viscosity

Physical Properties - Density Density is a physical property of matter that can be very useful. Density is a physical property of matter that can be very useful. It can be used to differentiate one material from another without performing complex experiments. It can be used to differentiate one material from another without performing complex experiments.

Density Calculating density requires two things: Calculating density requires two things: Mass Mass Volume Volume Dividing the mass by the volume allows you to calculate density. Dividing the mass by the volume allows you to calculate density.

Chemical Properties Chemical properties of matter are properties that describe how a substance reacts with another when forming a new substance: Chemical properties of matter are properties that describe how a substance reacts with another when forming a new substance: –Burning (combustibility) –PH balance (level of acidity)

Chemical and Physical Changes – Telling the Difference Sometimes it is difficult to tell the difference between chemical and physical changes. Sometimes it is difficult to tell the difference between chemical and physical changes. So how do you know? So how do you know? If two or more of the following occur then you probably have a chemical change. If two or more of the following occur then you probably have a chemical change.

Signs of Chemical Changes Heat is produced or absorbed. Heat is produced or absorbed. The starting material is used up. The starting material is used up. A new colour appears. A new colour appears. A starting colour disappears. A starting colour disappears. A material with new properties forms. A material with new properties forms. Gas bubbles form in a liquid. Gas bubbles form in a liquid. Grains of solid precipitate form in a liquid. Grains of solid precipitate form in a liquid.

Signs of Chemical Change Even with this list there is no guarantee. Even with this list there is no guarantee. To be certain you must perform tests both before and after the change. To be certain you must perform tests both before and after the change.

Homework Finish reading section 5.1. Finish reading section 5.1. Complete questions 1-4 on p.169. Complete questions 1-4 on p.169. Vocabulary Vocabulary –Solution –Mechanical Mixture –Density –Combustibility