Which is the best evidence that a chemical change has occurred?
A) change of state
B) release of energy
C) temperature change
D) formation of a new substance
D) formation of a new substance
Joelle noticed that when she uses the brakes on her bicycle while she is traveling at a slow speed, she stops moving immediately. When she is riding much faster; it takes more time for the bike to come to a stop after she applies the brakes.
Which is the best explanation for this observation?
A) The brakes are designed to be used at low speeds.
B) Joelle and her bike have more kinetic energy at higher speeds.
C) There is more friction between the bike and the ground when the bike is moving slower.
D) Moving at higher speeds increases the mass of the bike so it requires more energy to stop its motion.
B) Joelle and her bike have more kinetic energy at higher speeds.
Which of these is the primary source of energy in food webs?
A) soil
B) sunlight
C) producer
D) consumer
B) sunlight
A scientist observes that both birds and snakes in the same ecosystem depend on the same mouse species as a food source. The relationship between the birds and the snakes is an example of
A) predation.
B) mutualism.
C) competition.
D) commensalism.
C) competition.
A) wind turbines
B) hydroelectric dams
C) fossil fuels
D) solar cells
C) fossil fuels
Which event is an example of a chemical change?
A) fog rising off a river
B) wood burning in a fireplace
C) ice cream melting in the sunshine
D) grinding peppercorn into pepper flakes
B) wood burning in a fireplace
A group of students built a ramp and rolled steel balls of different sizes down the ramp onto the floor. THen they measured how far each ball rolled from the bottom of the ramp.
Which statement correctly explains the differences in the distances that the balls rolled?
A) Friction increased as mass increased.
B) Velocity increased as mass increased.
C) Acceleration increased as mass increased.
D) Kinetic energy increased as mass increased.
D) Kinetic energy increased as mass increased.
A food chain is shown.
What is the abiotic factor in this food chain?
A) Sunlight
B) Grass
C) Rabbit
D) Snake
A) Sunlight
An ocean food chain is shown.
Which organism gets its energy directly from the Sun?
A) phytoplankton
B) krill
C) fish
D) sea lions
A) phytoplankton
Which of the following is believed to be one cause of global warming?
A) atmospheric rise of carbon dioxide
B) hot air from air conditioner exhaust
C) methane gas escaping from landfills
D) body heat generated by overpopulation
A) atmospheric rise of carbon dioxide
When iron combines with oxygen in a moist environment, rust forms because of a
A) chemical reaction
B) physical reaction
C) change in density
D) change in temperature
A) chemical reaction
The mass of the basketball shown below is 4 times the mass of the baseball.If the two balls are moving at the same speed, and the baseball has a kinetic energy of 10.0 J, what is the kinetic energy of the basketball?
A) 2.5 J
B) 10.0 J
C) 20.0 J
D) 40.0 J
D) 40.0 J
4x the mass of the baseball
Baseball's kinetic energy is 10J
4 x 10 = 40
Students kept some crickets in a classroom tank. The tank was kept in an area where it would get several hours of sunlight a day. The tank contained one area with water, and another area with soil where plants were growing.
From which source did the crickets gain the energy they needed for cell processes?
A) the soil
B) the water
C) the plants
D) the sunlight
C) the plants
A tick attaches to a deer and consumes blood, harming the deer. This is an example of which type of relationship?
A) predator-prey
B) mutualism
C) parasite-host
D) commensalism
C) parasite-host
Suppose most of the water, carbon dioxide, and methane gases were taken out of Earth's atmosphere. How would this most likely affect Earth's temperature?
A) The greenhouse effect would be stronger, so Earth's temperature would increase.
B) The greenhouse effect would be stronger, so Earth's temperature would decrease.
C) The greenhouse effect would be weaker, so Earth's temperature would increase.
D) The greenhouse effect would be weaker, so Earth's temperature would decrease.
D) The greenhouse effect would be weaker, so Earth's temperature would decrease.
Which activity is an example of a chemical change?
A) sugar dissolving in water
B) water evaporating in air
C) lighting a match
D) freezing water
C) lighting a match
A bus moves down the street at a rate of 500 meters per minute for 5 minutes. Which graph shows the motion of the bus?
A)
Examples of some organisms found in a forest ecosystem are shown.
How would energy most likely flow between the organisms?
A) grasshopper, frog, snake, hawk
B) hawk, snake, grasshopper, frog
C) snake, grasshopper, frog, hawk
D) frog, grasshopper, hawk, snake
A) grasshopper, frog, snake, hawk
Which of these is a threat to the survival of an ecosystem?
A) predator-prey population cycles
B) less biomass at higher levels of the food web
C) a shrinking variety of plant species
D) competition among some consumer populations
C) a shrinking variety of plant species
The diagram below shows a process in Earth's atmosphere.
Which process does the figure show?
A) water cycle
B) smog formation
C) ozone depletion
D) greenhouse effect
D) greenhouse effect
An electrical circuit can be used to break down water into hydrogen and oxygen. In this process, electrical energy produces
A) kinetic energy
B) physical changes
C) chemical changes
D) potential energy
C) chemical changes
During an investigation on energy, Seth rolls marbles of four different masses down a ramp.
Which size marble will have the greatest kinetic energy?
A) 2 grams
B) 3 grams
C) 5 grams
D) 6 grams
D) 6 grams
Energy flows in an ecosystem through food webs. Which form of energy is the least available for reuse in a food web?
A) heat energy
B) sunlight energy
C) energy from producers
D) energy from consumers
A) heat energy
Some plant species and animal species depend on each other. Which of these animals help thousands of plant species to reproduce?
A) squirrels
B) earthworms
C) honeybees
D) beetles
C) honeybees
Carbon dioxide is one of the greenhouse gases that help keep Earth warm enough to support life. Increasing the carbon dioxide in the atmosphere increases the temperature. Below are two tables that show natural and human-made sources of carbon dioxide.
Earth's atmosphere is getting warmer. Does the data in the tables enable you to determine whether humans are responsible for an increase in Earth's atmospheric temperature?
A) No, the data does not show the locations of the sources of natural and human-made carbon dioxide in the atmosphere.
B) No, the data does not show how the amounts of carbon dioxide from human and natural sources have changed over time.
C) Yes, the change is due to human-made sources of carbon dioxide.
D) Yes, the change is due to natural sources of carbon dioxide.
B) No, the data does not show how the amounts of carbon dioxide from human and natural sources have changed over time.