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52 Cards in this Set
- Front
- Back
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Matter
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Anything that takes up space and has mass.
Made up of atoms or molecules in various arrangements |
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Atoms
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Made up of even smaller particles- protons, neutrons and electrons
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Neutrons and protons
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Make up most of the mass and can be founf at the atomic nucleus at its center. Protons have a positive charge
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Electrons
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Have a negative charge equal and opposite to the proton's positive
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Neutral vs. Ionized atoms
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neutral- the # of protons is equal to the # of electrons
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4 Types of Matter
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Solid, Liquid, Gas and Plasma
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Physical properties of Matter
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Color: The human eye's response to light either reflected or emitted by matter
Density: The amounst of mass that is contained in a unit volume by a given substance Hardness: the resistance to penetration offered by a given substance *Physical changes do not involve one substance changing into another EX: Water can change from gas to liquid water to solid (ice) but water molecules don't change |
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Thermal Properties of Matter
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When heated or cooled matter undergoes phase changes, meaning that a substance changes state
EX: Solid to liquid to gas. When cooling reverse progression usually seen |
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Electrical Properties of Matter
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Matter can be classified as a conductor or a nonconductor. Conductors have a relatively high # of free electrons (loosely bound electrons that can wander from atom to atom within the material, belonging to no particular atom- free electrons also called "valence" electrons)
*Conduction occurs when battery terminals are connected across a material object, causing the free electrons to flow as current through the object. *The direction of flow is towards the positive battery terminal as it attracts the negative electrons, while the negative terminal repels them. *In General metals are good conductors and non-metals are not, because metals have abundant free electrons/ |
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Chemical Properties of Matter
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*Chemical changes occur when a substance is changed into something else
EX: When paper is burned the molecules are altered, transforming the paper into gases and ash. |
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Molecules
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Atoms grouped together with other atoms.
Some molecules are made up of the same element, others are made up of combinations of elements. Can contain anywhere from 2 to thousands of atoms |
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Compound
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Any substance made up of 2 or more different elements
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Organic Compound
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A molecule that includes carbon atoms (all living things and fossils of once living things).
Organisms contain carbon. |
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Periodic Table of Elements
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So far scientists have discovered 109 atoms with different combinations of protons, neutrons and electrons. These 109 substances are called elements.
Location of a substance in the periodic table determines how it will react with another substance (more seperated the groups the more likely the possibility for reaction |
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Common Elements
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Hydrogen, oxygen, iron
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Acids
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Substances that have a sour taste
Weak acids like citric acids in lemons and limes or aceitic acids like vinegars are found naturally in the foods we eat. Even cola drinks are acids. Hydrochloric acid is in our bodies to help start processes like digestion and fight germs. Very strong acids corode through materials including wood, rubber and metal |
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PH Scale
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What scientists use to measure the strength of acids and bases.
Pure water has a pH of 0 |
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Bases
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Also called alkalis.
Feel soapy, slippery with strong solutions caustic to the skin. Like acids they can corode other materials. |
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Litmus paper
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Special paper used to measure PH of substances.
turns red- substance is an acid turns blue- substance is a base Intensity of the color also shows if the base or acid is strong or weak. |
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Position
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Refers to the location of an object.
EX: an object is 2M to the right of an origin on the x axis or that it is 5M to the left of an origin. Written +2M or -5M |
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Displacement
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Refers to how far an object has moved
EX: Initial position of -2M and final position of 7M, displacement is 9M |
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Speed
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The time-rate of displacement.
To find average speed over some time we divide the displacement by the time. EX: displacement of 9 occurs over 4.5 Seconds. Speed is 9/4.5 m/s or 2m/s |
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Velocity
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Is a speed with a specified direction.
EX: +2m/s is to the right, -2m/s is to the left |
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Acceleration
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The rate of velocity change.
To find average acceleration over some time we divide the change in velocity by the time EX: 2m/s/s |
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Newton's 1st Law of Motion
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An object at rest tends to remain at rest and an object in motion tends to continue moving in a straight line at a constant speed.
Inertia is the tendency of objects at rest to remain at rest or at motion to remain in motion. A force is needed to overcome inertia |
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Newton's 2nd Law of Motion
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If you apply force to an object, you will either change its speed, change its direction or both
EX: the harder the pitcher throws the faster the ball will travel. Also says that you will have to use more force to move or stop a massive object than to move or stop a smaller object. |
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Newton's 3rd Law of Motion
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For every action there is an equal and opposite reaction.
Forces or "actions" come in pairs. If you hit a tennis ball with a racket the racket exerts an opposite force on the ball and the ball exerts an opposite force on the racket. You can feel the reaction when your racket slows down as the ball hits it. |
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Simple Machines
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Used when small forces are exerted over long distances to accomplish difficult tasks.
EX: A pulley, a lever (like a nail puller on a hammer or a see-saw type device) |
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Power
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The speed of work. Power is equal to the work done divided by the time it takes to do it.
Power = work/time |
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Work
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Moving something against resistance.
Work = Force (Displacement) |
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Energy
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The ability to do work.
Takes many forms. Different forms of energy can be changed from one kind to another, but energy itself can't be created or destroyed in ordinary chemical or physical processes. All energy is potential or kinetic. Potential energy can always be changed into kinetic energy and back again into potential energy. |
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Potential Energy
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Has the energy stored in it. It is waiting to do work.
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Kinetic Energy
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"Active" energy. Objects with kinetic energy are moving.
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Forms of energy
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Solar, chemical, electrical, magnetic, nuclear, sound, light and electromagnetic.
EX: When you turn the lights on in the car chemical energy stored in the batery is converted into electrical energy (current flowing through the circuitry) which is then converted into both heat and light energy in the headlamp filament. Solar radiation is used in some parts of the world to heat water. Lightning strikes produce thunder because some of the electrical energy in the lightning strike sets up vibrations in the air which are converted to sound. *Total energy in a system is conserved but may be changed from one form to another, as in an electrical motor or generator. |
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Heat
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A form of kinetic energy. Is created when atoms and molecules in a substance move backward and forward very rapidly. As a substance gets hotter its molecule move faster and faster
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Temperature
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Tells how hot or cold something is. Also tells you whether heat is flowing into a substance or flowing out of it
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3 ways to measure temperature
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THERMOMETERS: Contain a substance that indicates temp of its surrounding by reaching the same temp as its surroundings
THERMOCOUPLES: Dissimilar metals joined together producing a small electrical signal OPTICAL METHODS: When certain solids (often metals) are heated to elevated temperatures they begin to glow. At first a dull red, then color mix starting w/yellowish white and at higher temps bluish white |
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How heat is transfered
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Heat flows from warmer to cooler bodies in 3 ways: radiation, conduction and convection
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Radiation
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Hot objects give off infrared light in waves that can travel through empty space and air. When this infrared radiation is absorber by a body it is changed to heat.
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Conduction
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When heat moves through one object to another.
EX: A metal spoon in a cooking pot on the stove, the spoon heats up too |
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Convection
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Hot air is not as dense as cool air, so the cooler air pushed the hot air upward. Heat can move from an energy aource in a circular pattern
EX: Hot air rises from the radiator, then cools and sinks and is heated again by the radiator and rises |
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Light
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Energy that acts on our eyes.
RADIATES- travels in straight lines in all directions from its source. Consists of tiny particles called photons |
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Light Source
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Anything that gives off light.
The sun is our most powerful light source. Other artificial sources- electric lights, flashlights or excited atoms (neon in neon lights) |
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3 Principal modes of light/matter interaction
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Vision, photosynthesis and photoemission
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Vision
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Light in the visible spectrum interacts with the rods and cones of the human eye, producing electrical signals which the brain interprets as color
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Photosynthesis
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The process by which chlorophyll containing organisms- green plants, algae and some bacteria- capture energy in the form of light and convert it into chemical energy
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Photoemission
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When light interacts with certain types of materials (usually alkai metals) photoemission can occure.
Electrons are emitted by the illuminated material EX: The TV camera where light images are converted to electron images |
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Properties of waves
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Light and sound waves.
Reflection, refraction and sound |
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Reflection
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Light travels in straight lines. We see objects around us because they reflect, or bounce light into our eyes. Light surfaces reflect more light back than dark surfaces.
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Law of Reflection
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light travels in perfectly straight lines called rays. When they hit a mirror (any shiny surface) they are reflected at an angle equal to the angle which the ray hit the mirror
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Refraction
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Light waves travel faster through air than through water, glass or other substances. When a light ray passes at an oblique angle from one material to another, its path typically appears to bend
EX: straw in a glass |
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Sound
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Is anything you hear.
Is really air vibrating, or moving back and forth quickly. EX: pluck string of guitar, starts vibrating and causes the air around it to vibrate too. The vibrations travel through the air to your eardrum and you hear sound. Travels through a vibrating object therough compression waves- the more the waves are compressed (or squeezed together) the louder the sound |
