Conservation of Mass and Energy L18.4
Conservation of Mass and Energy L18.4
Elements & compounds P8.5
Physical Properties of Matter
Properties of Waves P10.3
Chemical & Physical Changes P9.2
100
In the oxygen cycle, which group of organisms replenishes a large portion of the atmospheric oxygen supply?
plants
100
This type of pure substance is made of only one kind of atom and cannot be broken down into simpler substances by chemical means.
What is an element?
100
A student stirred sugar into a beaker of warm water until the sugar crystals were no longer visible.
Explains this observation.
Sugar is soluble in water, meaning it dissolves.
100
This is the distance between two consecutive crests or troughs in a wave.
What is wavelength?
100
When iron reacts with oxygen to form rust, this type of change occurs because a new substance is created.
Chemical change
200
The natural cycling of oxygen between organisms and their environment is most directly accomplished through which of the following pairs of processes?
photosynthesis and respiration
200
Atoms are made up of subatomic particles, including protons. Which of these describes a proton?
has positve charge
200
Students carefully compared equal-sized cubes of wood and aluminum by placing them in a container of water. The wood floated, but the aluminum sank. Which property are the students most likely comparing?
Density of the cubes
200
This property measures how many waves pass a point in a given amount of time.
Frequency
200
The list below describes the process of making popcorn.
- Heat is applied to the water molecules inside a popcorn kernel.
- The water turns to steam, which builds up pressure.
- The pressure causes the kernel to burst open, and the fluffy starch inside expands outward, changing the kernel’s shape.
How does the water turning to steam compare to the popcorn kernel changing shape?
What kind of change happened?
Both the water turning to steam and the kernel changing shape are physical changes.
300
Which diagram correctly models the movement of energy and matter in an ecosystem?
A. 
B.
A
300
A student says salt is not made of elements because it looks different than either sodium or chlorine. What would be the best explanation?
Salt is a compound formed when elements combine and create new properties.
300
A group of students connected a copper wire and a rubber band to a battery and a small light bulb. The light bulb turned on with the copper wire, but not with the rubber band. Which property are the students testing?
Electrical conductivity of the materials
300
When a wave hits a surface and bounces back, this process occurs.
reflection
300
A student placed an effervescent tablet into two beakers: one with cold water and one with hot water. The tablet in hot water dissolved and reacted much faster. What most likely explains this observation?
Hot water increases the rate of the chemical reaction.
400
A fire burns a large portion of a forest. What impact would this event likely have on the carbon cycle?
A sudden release of carbon into the atmosphere
400
A student creates the model shown below to represent the structure of an atom.
Which part of the atom is located in the area outside the nucleus?
electron
400
Water has a density of 1.0 g/ml. To determine if an object sinks or floats in water, what must you compare?
The density of the substance relative to water.
400
This type of wave requires a medium to travel, like sound waves moving through air.
mechanical wave
400
Maria records her observations of a sample during a lab investigation:
Test Characteristic Observed. Yes/No
1. Reflects light/Shiny. Yes
2. Floats in water. No
3. Maintains color when wet. Yes
4. Forms bubbles when placed in acid Yes
Which test provides the strongest evidence of a chemical change?
Test #4
500
At position Y, carbon is most likely to be in which of the following forms?
Carbon dioxide
500
Look at the diagram below.
What does this diagram best represent?
Atoms combining to form a compound
Explanation
The image shows atoms of different elements joining together chemically to form a new substance, which is a compound. This is how compounds like water are created.
500
A group of students placed a plastic spoon and a metal spoon into a pot of hot soup. After 2 minutes, the metal spoon was hot to the touch, while the plastic spoon was not. Which property are the students most likely comparing?
Thermal conductivity of the spoons
500
As the frequency of a wave increases, this property decreases if the wave speed stays constant.
What is wavelength?
500
Unlike melting ice, this process involves a substance combining with oxygen to produce heat and light, forming entirely new substances
What is combustion?