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Grade 8 Final
Question | Answer |
---|---|
How are particles in objects in a solid state? | Packed tightly together in fixed positions |
How are particles in objects in a gas state? | Spread out and fill all the space available to them |
How are particles in objects in a liquid state? | Free to move in a container but remain in close contact with one another |
Melting point | Temperature at which a solid changes into a liquid, and each substance has its own distinct melting point |
What happens when an inflated balloon is exposed to cold air? | The volume inside the balloon decreases |
How does heat transfer occur? | Only from warm objects to colder objects |
How does heat transfer through convection? | When heated air moves from baseboard heaters to the rest of a room |
Viscosity | The resistance of a liquid of flowing |
What are examples of chemical formulas? | H2O and CO2 |
What do chemical formulas indicate? | The type and amount of each element in a molecule |
What does the element's atomic number represent? | The number of protons in that atom |
What kind of elements are located in Group 1 on the periodic table? | The most reactive metal elements |
Elements | Substances that cannot be broken down chemically into other substances |
Mass | The amount of matter in an object |
How is the volume of a liquid measured? | By using a graduated cylinder |
Density | The measurement of how much mass is contained in a given volume |
How do you find density? | Mass/Volume |
What is burning wood an example of? | Chemical change |
What are signs of chemical changes? | Change in color, odor, temperature, formation of a precipitate, bubbling/fizzing |
What is the difference between alloys and pure metals? | Alloys resist corrosion while pure metals corrode (like rusting) |
Mixtures | When substances are not chemically combined |
Constraint | Any factor that limits or restricts the design of a technology product |
Troubleshooting/Redesigning | Process of analyzing and fixing a design flaw |
Potential Energy | Stored energy |
Kinetic energy | Energy of matter in motion |
What do endothermic changes do? | Absorb energy like when ice melts |
What happens during photosynthesis? | Plants transform electromagnetic energy from the sun into chemical energy |
Temperature | The measure of the average kinetic energy of the individual particles in an object |
Gravitational potential energy | Potential energy that depends on height |
Radiation | The transfer of heat through electromagnetic waves |
How do you find the average speed? | Distance/Time |
Motion | When an object's distance from another object is changing |
Momentum | The product of an object's mass and its velocity |
Inertia | The tendency of an object to resist change in its motion |
Acceleration | Change in direction and/or speed |
Velocity | The speed and direction of an object |
Reference point | A place or object used for comparison to determine if something is in motion |
Friction | The force that once surface exerts on another when the two rub against each other |