Vocabulary
Define "matter."
Any of these answers are acceptable:
- Matter is everything.
- Matter is all around us.
- Matter is solids, liquids and gases.
Define "mixture."
A combination of two or more substances where no chemical reaction has occurred.
True or False: A mixture is a combination of substances that experience a chemical reaction.
False. Mixtures cannot undergo a chemical reaction.
Explain how "evaporation" can be used to separate materials.
Evaporation is when a liquid turns into a gas. It can be used to separate soluble solids from a liquid, but you need heat and time. Example: if you mix salt into water, then evaporate the water out, you can recover the salt again.
What are the three states of matter?
Solids, liquids and gases.
Define "indicator."
An indicator is a substance that shows if something is basic or acidic.
Define "solution."
A homogeneous mixture where one substance is fully dissolved into another substance.
True or False: Batter turning into a cake is an example of a chemical reaction.
True.
Magnetism can be used to separate two solids if one of them has magnetic properties. For example, if a teacher mixed staples and erasers in a cup, they could use a magnet to recover the staples.
Describe the properties of the three states of matter.
Solids retain their shape and do not flow.
Liquids flow and take the shape of their containers.
Gases flow and take up all of the space available.
Define "saturated."
When a mixture/solution is saturated, it means it can no longer hold any more solute.
In a mixture, two or more substances are combined but no chemical reaction can occur.
In a solution, two or more substances are combined, but the solute has to be dissolved fully into the solvent.
True or False: Ice melting into water is an example of a chemical reaction.
False.
Explain how "density / a separating funnel" can be used to separate materials.
Density can be used to separate solids, liquids or gases. If substances of different densities are put into a separating funnel, they will layer in the funnel based on how heavy they are. For example, if corn syrup, water and cooking oil are put into a funnel, they will naturally separate because they have different densities.
Name two examples of safety rules for Classroom Chemistry.
Never reach across a flame.
Never run or push someone in a lab.
Never taste a chemical unless your teacher asks you to.
Read and follow all directions exactly as they are written. If in doubt, ask for help!
Never mix chemicals or perform tests without your teacher's permission.
Keep your work area clean, etc.
Define "reversible" and "irreversible," and explain how they are connected to chemical and physical reactions.
Reversible can be undone.
Irreversible cannot be undone.
Physical reactions are reversible. Chemical reactions are irreversible.
Provide two examples of a sold + liquid mixture.
Cereal + milk
Sugar + water, etc.
True or False: Sand and water being mixed together is an example of a physical reaction.
True
Explain how "settling" is used to separate materials.
Settling can be used to separate solids from liquids. Settling is when particulates (small pieces of something) fall to the bottom of a liquid and form a sediment. If you were to put sand in a glass of water, the sand would settle on the bottom.
What is the process of forming a solution?
Add a solute to a solvent and stir. The solute needs to dissolve fully for the substance to be a solution.
Define "solute" and "solvent," and explain how they are connected to solutions.
A solute is the substance being dissolved. A solvent is the substance in which the solute is dissolved. Solutes and solvents are connected to solutions because for a mixture to be a solution one substance (solute) has to be dissolved fully into another (solvent).
Name two examples of solid + solid mixtures.
Mixtures:
- Salad = lettuce + tomatoes + cucumbers
- Sand + sugar
- Nuts + bolts
Name at least 3 of the 5 signs of a chemical change.
- Odour
- Energy Change
- Gas Bubbles
- Precipitate Formation
- Colour Change
Explain how "sublimation" is used to separate materials.
Sublimation is used to separate a mixture of solids, one of which sublimes. Sublimation is when a solid changes directly to a gas without going through the liquid stage. If you use sublimation to separate two materials, one will change to a gas form and the other will remain a solid.
Explain surface tension.
Surface tension is a force that is on the surface layer of a liquid that causes the layer to behave like an elastic sheet. It is caused by cohesion. It allows droplets of water to remain on your skin without spreading out, and allows insects to be able to walk on water.
Define "homogeneous" and "heterogeneous." Provide one example of each.
Homogeneous means it looks the same throughout - the components are uniformly distributed. Example: chocolate milk, saltwater, sugarwater, etc.
Heterogeneous means the individual components can still be identified by looking. Example: Pizza, salad, cereal with milk, etc.
Explain the relationship between mixtures and solutions to the words homogeneous and heterogenous.
Mixtures can be homogeneous or heterogenous.
Solutions can only be homogeneous because one substance needs to dissolved fully into another substance.
Explain the relationship between physical reactions, chemical reactions, reversible reactions and irreversible reactions.
Chemical reactions are irreversible - they cannot be undone.
Explain how "filtration" and "sieves" are different from one another.
Filtration is used to separate insoluble solids from a liquid. Sieves are used to separate solids from other solids of a smaller size. They are similar, but not the same.
How can you tell if something is basic or acidic? Use knowledge about the pH scale in your answer.
If you test a material using an indicator and the pH scale, anything from 0-6 is acidic, anything from 8-14 is basic, and anything at 7 is neutral.