Elements and Compounds
Which ones are PURE substances - elements or compounds?
elements
If a car went 100 miles in 2 hours, what was its average speed?
50 miles per hour
Name three physical properties that describe most metals.
shiny, conduct electricity, malleable, ductile, solid
A rubber ball is dropped to the floor from a height of 2 meters. It bounces 4 times and then stops. Where did the ball have the greatest kinetic energy?
At the bottom of the first drop
What energy transformation occurs when an electric toaster is plugged in?
electrical to thermal
Which are listed on the periodic table -- elements or compounds?
elements
If it took 3 seconds for a ball to roll 12 meters, how fast was it rolling?
4 m/s
What is the formula to find the density of a substance?
density = mass/volume
A child is pulling his sled up the hill. Is the sled gaining kinetic or potential energy?
potential
What energy transformation happens when a person turns on a battery-operated radio?
chemical to electrical to sound
What is the most common compound on our planet?
H2O (water)
If a car took 2 hours to go 100 miles, how far could it go in 3 hours?
150 miles
Describe malleability and ductility.
malleability - the ability to bend and be formed when hit by a hammer - not break
ductility - ability to be drawn into a wire
T or F: Potential and kinetic energy are always transferring back and forth as long as motion is occurring.
True
What energy transformation happens when a propane gas stove is used to boil water in a teakettle?
chemical to thermal (and light) to sound (if the teakettle whistles)
T OR F? Elements are represented by a chemical symbol, usually one or two letters.
TRUE
If the motion of a runner is shown on a graph (distance = y, time = x) what does a flat line mean?
The runner has stopped.
Is color the best way to identify a mineral? Why or why not?
Many minerals may have the same color.
Kinetic energy is the energy of __________.
motion
What are some benefits to using alternative, renewable energy sources?
less pollution, less costly in long run, slow global warming
____ are made up of two or or more elements.
Compounds
400 mph
What are some other physical properties (besides color) to help identify minerals?
streak, luster, hardness, crystal shape, density
Potential energy is __________energy that can be transferred to kinetic energy.
stored
What energy transformation is happening when a person rides a bike?
chemical (food as fuel) to mechanical