Notes G. States of Matter

Daily Quiz Question 4.21.2014 What are the four states of matter?

Notes G. States of Matter Matter-makes up all substances, whether it is a solid, liquid or gas. Molecules, atoms and sub-atomic particles are all matter. The major properties of matter are that it takes up space, has mass and attracts other matter with gravity.

Notes G. States of Matter Kinetic Theory All matter is made up of constantly moving atoms or molecules (particles). The motion of these particles determines whether a substance is a solid, liquid, or a gas – the KINETIC THEORY Kinetic= motion. The energy of an object has because of its motion is called kinetic energy.

Forces Intermolecular forces- forces of attraction or repulsion which act between neighboring particles. Intramolecular forces- forces which keep a molecule together.

Notes G. States of Matter 1. Solid 2. Liquid 3. Gas 4. Plasma

Notes G. States of Matter Gases- Particles of a gas are: Relatively far apart with no intermolecular forces of attraction or repulsive forces between. Motion of particles is rapid, constant and random (independent of one another). Have no definite shape or volume. The volume of a quantity of gas is dependent on temperature and surrounding pressure Collision between particles is a gas are perfectly elastic.

Notes G. States of Matter Liquid Particles of a liquid are: In a liquid, the particles are farther apart, but they are still close enough to have intermolecular forces of attraction between atoms. Motion between particles is constrained by the volume of the liquid. Have definite volume. Takes the shape of the container. Liquids are more dense than gases but less dense than solids.

Notes G. States of Matter Solids Particles of a solid are: In a solid, the particles are so close that the intermolecular forces of attraction confine the material to create the specific shape (organized atom arrangement). In solids, the motion of the particles is severely constrained to a small area, in order for the solid to maintain its shape. Have definite volume. Have definite shape. Most dense.

Notes G. States of Matter Plasma Particles of plasma: Similar to a gas, but charged particles with extremely high energy Exists at very high temperatures Rare on earth, but found in universe in stars

Notes G. States of Matter Kinetic Energy and Temperature As a substance is heated, its particles absorb energy some of which is stored within the particles. The remaining absorbed energy speeds up the particles, increasing their kinetic energy, therefore increasing the temperature.

Notes G. States of Matter Physical Change- A change in which some properties of a material change, but the composition of the material does not change.

Notes G. States of Matter

Notes G. States of Matter Endothermic- Process that absorbs heat (energy) from the surroundings. Exothermic- Process that releases heat (energy) to the surroundings.

Notes G. States of Matter Freezing- Liquid  solid, energy is released, forces increase Melting- Solid liquid, energy is absorbed, forces decrease Deposition- Gas solid, energy is released, forces increase Sublimation- Solid gas, energy is absorbed, forces decrease

Notes G. States of Matter Evaporation- Liquid gas, energy is absorbed, forces decrease Condensation- Gas liquid, energy is released, forces increase

Notes H. Transfer of Heat Energy Heat- energy that transfers from one object to another because of a temperature difference between the objects. Temperature- the measure of the average kinetic energy of particles in matter

Notes H. Transfer of Heat Energy Phase Change Diagrams- Temperature vs. Time A transfer of energy occurs at every change of phase. Heat of Fusion – the amount of energy needed to change any substance from solid to liquid (or a liquid to solid). Heat of Vaporization – the amount of energy required to change any substance from liquid to gas (or a gas to liquid).

Notes H. Transfer of Heat Energy Phase Change Diagrams- Temperature vs. Time

Notes H. Transfer of Heat Energy Magic Ice Demo What happened? Why? Balloon Demo

Notes H. Transfer of Heat Energy If you have ever left a silver spoon in very hot soup, you will notice that the whole spoon gets hot. Thermal energy is transferred from the hot end of the spoon through the entire length, its called conduction.

Notes H. Transfer of Heat Energy Conduction- the transfer of heat energy from an area of higher temperature to an area of lower temperature due to the interaction of neighboring particles.

Notes H. Transfer of Heat Energy Conduction Particles often collide with each other. When this happens, energy is transferred from the faster (hotter) moving particle to the slower (cooler) moving particle. This makes the slower moving particles increase in speed. When molecules in a substance are made to move faster, they get warmer. The warmer an object gets, the more kinetic energy and therefore, thermal energy it contains: Kinetic energy is the energy of motion Thermal energy is the total energy of the atoms.

Notes H. Transfer of Heat Energy Conduction If conduction of heat relies on collisions between neighboring particles, which would make the best conductor? Why? - Solids - Liquids - Gases - Plasma

Notes H. Transfer of Heat Energy Conduction Good conductors of heat are metals with loose electrons – silver, copper, iron, etc. Poor conductors are called insulators. These don’t have loose electrons – wool, wood, paper, Styrofoam, etc. Air is a poor conductor of heat, so things with air spaces in them are sometimes used as insulators.

Notes H. Transfer of Heat Energy Bottle Demo What happened? Why?

Notes H. Transfer of Heat Energy Convection Convection is the transfer of heat by motion of a fluid (a fluid is a liquid or a gas), or by currents.

Notes H. Transfer of Heat Energy Convection Convection works in fluids in the following way: Fluid is heated from below and the molecules on the bottom start moving faster. The molecules on the bottom spread apart and become less dense. The less dense molecules move up to the top, as the denser, cooler fluid moves to the bottom. The convection current will keep stirring this way. The warmer fluid will always move away from the heat source and the colder will move towards it.

Notes H. Transfer of Heat Energy Convection Sometimes convection works in gases like it does in fluids: -Warm air expands and therefore becomes less dense. -This less dense air rises through the surrounding cooler air. -Once the warm air reaches air with the same density, it stops rising. -As air expands, it cools. -As it is compressed, it gets hotter.