Definitions
have atoms and molecules that are closely packed together.
Solids
Water can take three forms: solid, liquid, or gas.
True
You can tell when a chemical change has occurred because…
a. the new substance will look exactly the same.
b. the new substance will be able to return to its original state.
c. the new substance may have a new colour, texture, melting point or boiling point.
C
Condensation is a change in states from Gas to ______.
Liquid
How can pressure increase the speed at which a change of state occurs?
Pressure can increase the speed at which a change of state occurs by breaking the matter into small pieces and allowing the effects of the cold or heat to take effect faster. For example, an ice cube can change into a liquid faster when broken down into smaller pieces of ice because each smaller individual piece will take a lesser time to melt than the one larger solid piece of ice. This is because more surface area of the original ice cube would be exposed to air/heat.
a change that is not reversible.
Chemical change
A change of state can occur by adding or removing heat.
True
The term “biodegradable” is defined as…
a. waste that is capable of being slowly destroyed and broken down.
b. waste that is not capable of being slowly destroyed and broken down.
c. a term relating to biology which refers to living things.
d. none of the above
A
A physical change is one that is ____________.
Reversible
Explain how matter that enters a landfill sight is managed.
Items that enter a landfill sight usually undergo a strict filtering and sorting system. Most materials are grouped together based on the similarities of their makeup. For examples, bricks, concrete, and cement are all put together in the same pile. Metals such as copper, steel, and brass, are all grouped together
the quantity of matter in something. Also known as weight.
Mass
Physical changes are irreversible while chemical changes are reversible.
False
have molecules that want to stick together but will separate if not held together by a container.
a. solids
b. liquids
c. gases
d. all the above
B
In the 2nd experiment you completed in this unit, you found that ___________ can help solids dissolve in water.
Heat
Explain the difference between a physical change and a chemical change and provide three examples for each.
A chemical change is not reversible. A physical change is reversible and can go back to its original state.
Physical- ice melting, water freezing, adding salt or sugar to water.
Chemical - burning wood, baking a cake, cutting paper, boiling rice.
have molecules that are completely free and are not bound to each other.
Gases
Vaporization is when a gas turns to a liquid.
False
In the 1st experiment you completed in this unit you found that when water changes states, its mass…
a. increases
b. decreases
c. stays the same
d. all of the above
C
In experiment 2, the jar with ________ and water was the only one to experience a chemical change because_________.
Rice.
the rice cannot go back to its original state. It has absorbed the water which caused it to become softer and larger.
Explain the main difference in the arrangement of molecules of each state of matter. Draw a picture to demonstrate your answer.
The main difference in the arrangement of molecules of each state of matter are how closely they are packed together. Solids have molecules that are very closely packed together. They are not able to move around very much. They are stuck in a set position unless otherwise acted upon from an external force. The molecules of a liquid are much farther apart than in a solid. Liquids flow and move in any direction unless they are contained by some external structure. The molecules of a gas are even farther apart than those of liquids. The molecules of gases are completely free; they are so spaced out that it is very difficult to see them with the naked eye.
any material or substance that forms physical objects and occupies space.
Matter
Sublimation is when a solid turns to a liquid.
False
When matter changes from a gas to a solid, this change is called…
a. melting
b. freezing
c. vaporization
d. deposition
D
Applying _______________ may assist in the conversion of one state to another.
Answer has three options, you must get all three.
Heat, cold or pressure
Explain the potential harms that using matter has on the environment. Give examples to support your answers.
After matter is used, if it does not decompose naturally the waste products can stay in landfill sights for hundreds to thousands of years. As landfill sights fill up they are shut down and often that land is deemed unusable for many years afterwards. Eventually new sights need to be scouted and more land taken up for waste. Sometimes items that are harmful to the environment are disposed of improperly and they can pollute the atmosphere or run down into the ground along the water table and get into a local community’s drinking water. Hazardous items must be disposed of in a particular manner and grouped together appropriately.