Chapter 4 Review: Matter The Particle Theory of Matter Physical and Chemical Change

What is Matter? Matter is anything that has mass. Mass is the amount of matter in an object. Volume is the amount of 3-dimensional space that an object takes up. There are two types of matter: – Living matter (plants, animals, bacteria) – Non-living matter (rocks, plaster, water)

States of Matter There are three states of matter: – Soild – Liquid – Gas Matter in different states exhibits different characteristics. These can be explained using the particle theory of matter.

Properties of Matter Properties of matter can either be qualitative or quantitative. There are physical properties and chemical properties of matter: – Physical properties are the properties that do not involve the making of new substances. – Chemical properties are the properties that involve the formation of new substances.

Characteristic Physical Properties These are the physical properties that make a substance different from most other substances. Melting point: temperature which the solid form of a substance becomes liquid Boiling point: temperature which the liquid form of a substance becomes a gas. Density: the amount of mass per unit volume (how tightly packed the particles are)

Chemical Properties Combustibility: the ability of a substance to burn (requires oxygen) Flammability: the ability of a substance to burn when exposed to a flame Light Sensitivity: the ability of a substance to change to a new substance in the presence of visible light.

The Particle Theory of Matter 1.All matter is composed of particles -These particles are the smallest pieces of matter that identify a substance. -If you take a substance and break it into successively smaller pieces, eventually you come to the smallest piece … a particle. -If you are able to break a particle further, you change the substance into something new.

The Particle Theory of Matter - The particles of one substance are the same. The particles of different substances are made of different particles. -Gold particles are all the same and are different from silver particles. -There is no difference between water partiles fond in Aurora and water particles found in Toronto.

The Particle Theory of Matter 2. There are attractive forces between particles -The closer particles are to each other, the stronger the force. -This is why substances like solids, with particles so strongly attracted to each other, are typically more dense than liquids or gases.

The Particle Theory of Matter 3. Particles are always moving. -Regardless of whether or not a substance appears to be still, the particles that make it up are moving. -In theory, when this movement stops, a substance has reached its lowest possible temperature.

The Particle Theory of Matter - The more energy particles have, the faster they move and the higher their temperature. -This movement is called heat or heat energy. -Temperature is a measurement of the speed of the particles.

The Particle Theory of Matter 4. All particles have spaces between them. -The distances between the particles change for different states. -Particles in a liquid have more space between them than particles in a solid. -Particles in a liquid have less space between them than particles in a gas.

Physical Change Physical Change: a change in matter in which no new substance is formed. This may be a temporary change in the physical properties of the substance (i.e. solid to a liquid) The particles in the substance remain the same. This does not involve the breaking and formation of new chemical bonds.

Examples of Physical Change Change of State – Solid to a liquid to a gas Change of Shape – E.x. a pane of glass is shattered Change ability to transmit light

Chemical Change Chemical Change: a change in matter in which at least one new substance, with new properties, is formed. Involves the breaking of bonds between atoms and the subsequent formation of new bonds between atoms.

Chemical Change Indicators If two or more of the following happen, there is a good chance a chemical change has occurred: 1.Heat is produced (gets hot) 2.Heat is absorbed (gets cold) 3.The reactants (starting materials) are used up. 4.A new colour appears

Chemical Change Indicators The starting colour of the substances disappears (becomes clear) A substance with new properties forms Gas bubbles form in a liquid (usually without heating the substance) Particles of solid precipitate form in a liquid