Question: What is the simplest form of matter that cannot be broken down into simpler substances by chemical means?

Answer: An element.

Question: What is a substance made up of two or more different elements that are chemically bonded together?

Answer: A compound.

Question: What is a combination of two or more substances that are not chemically bonded?

Answer: A mixture.

Question: Is water (H2​O) an element, a compound, or a mixture?

Answer: It is a compound.

Question: Is oxygen (O2​) an element, a compound, or a mixture?

Answer: It is an element.

Question: Is salt dissolved in water an element, a compound, or a mixture?

Answer: It is a mixture.

Question: What is the smallest unit of an element?

Answer: An atom.

Question: What is the smallest unit of a compound that still has the properties of that compound?

Answer: A molecule.

Question: Can the components of a mixture be separated by a physical change?

Answer: Yes.

Question: Can the components of a compound be separated by a physical change?

Answer: No, they must be separated by a chemical change.

Question: What is the chemical symbol for the element Gold?

Answer: Au.

Question: What is the chemical symbol for the element Carbon?

Answer: C.

Question: What is the chemical formula for carbon dioxide?

Answer: CO2​.

Question: What type of mixture has a uniform composition throughout, like saltwater?

Answer: A homogeneous mixture.

Question: What type of mixture has a non-uniform composition where you can see the different parts, like a salad?

Answer: A heterogeneous mixture.

Question: When a substance is formed from a chemical reaction, are its properties generally the same as the original components, or are they different?

Answer: They are different.

Question: How would you separate a mixture of sand and water?

Answer: By filtration.

Question: How would you separate a mixture of iron filings and sand?

Answer: By using a magnet.

Question: When you dissolve sugar in water, what is the sugar called?

Answer: The solute.

Question: When you dissolve sugar in water, what is the water called?

Answer: The solvent.

Question: Is air an element, a compound, or a mixture?

Answer: It is a mixture.

Question: Is a gold bar an element, a compound, or a mixture?

Answer: It is an element.

Question: Is table saltSodium Chloride-  (NaCl) an element, a compound, or a mixture?

Answer: It is a compound.

Question: The process of melting ice is a physical change. Does the water’s chemical identity change?

Answer: No.

Question: The process of burning wood is a chemical change. Are new substances formed?

Answer: Yes.

Question: Is milk a homogeneous or a heterogeneous mixture?

Answer: It is a homogeneous mixture (though it is technically a colloid, which is a type of homogeneous mixture).

Question: Is pizza a homogeneous or a heterogeneous mixture?

Answer: It is a heterogeneous mixture.

Question: What is a specific type of homogeneous mixture where one substance dissolves into another?

Answer: A solution.

Question: How can you separate a mixture of salt dissolved in water to get the salt back?

Answer: By evaporation.

Question: What is a major difference between a compound and a mixture?

Answer: In a compound, the elements are chemically bonded. In a mixture, they are physically combined.

Question: The components of a compound have a fixed ratio. Do the components of a mixture have a fixed ratio?

Answer: No, they have a variable ratio.

Question: Can a single element be a molecule?

Answer: Yes, if two or more atoms of that element are bonded together (e.g., O2​).

Question: A substance that cannot be broken down into simpler substances is called what?

Answer: An element.

Question: Is rusting an example of a physical or a chemical change?

Answer: A chemical change.

Question: What method could you use to separate a mixture of small pebbles and sand?

Answer: Sifting or sieving.

Question: What is the chemical formula for water?

Answer: H2​O.

Question: What does the “2” in H2​O mean?

Answer: It means there are two hydrogen atoms in one molecule of water.

Question: Is a bowl of cereal with milk an example of a homogeneous or a heterogeneous mixture?

Answer: It is a heterogeneous mixture.

Question: What is the process of turning a liquid into a gas to separate a dissolved solid called?

Answer: Evaporation.

Question: When a new substance is formed with new properties, is it a mixture or a compound?

Answer: A compound.

Question: What is the difference between an atom of an element and a molecule of a compound?

Answer: An atom is a single unit of one element, while a molecule of a compound is a group of two or more different atoms bonded together.

Question: The chemical symbol for Sodium is Na. Is this an element, a compound, or a mixture?

Answer: An element.

Question: Is bronze, which is an alloy of copper and tin, an element, a compound, or a mixture?

Answer: A mixture.

Question: What is the general name for a mixture where a solid is dissolved in a liquid?

Answer: A solution.

Question: If you mix oil and vinegar, they form separate layers. What kind of mixture is this?

Answer: A heterogeneous mixture.

Question: Can elements be broken down by chemical reactions?

Answer: No.

Question: What is the chemical formula for a compound made of one carbon atom and two oxygen atoms?

Answer: CO2​.

Question: What is a substance called if its composition can be varied?

Answer: A mixture.

Question: What is a substance called if its composition is fixed?

Answer: A pure substance (either an element or a compound).

Question: Are atoms physically or chemically combined to form a molecule?

Answer: Chemically combined.