Compound and Mixture _2_Lesson

Compound and Mixture _2_Lesson

Chemical Formula 

•  a representation of a substance (compound) in which the elements are represented by their symbols and subscripts represent the number of atoms of each element

• Possible examples may include: CO2: carbon dioxide CO: carbon monoxide H2O: water NaCl: sodium chloride C6H12O6: glucose CaCO3: calcium carbonate SiO2: silicon dioxide

Compound 

• A pure substance made by chemically combining two or more elements

• Represented by a chemical formula

• The proportion of each element in a compound is constant (if the subscript is changed, the substance is changed)

Elements 

• Made up of ONE type of Atom 

• Cannot be broken down chemically into simpler substances 

• Organized on the Periodic Table of the Elements 
  

• Represented by a Chemical symbol 

• Properties can be used to identify different elements 

  
  
  

Sample questions

Multiple Choice

If I have a mixture of wooden blocks and metal blocks. What is a fast way to separate them?

• relative density (put them in water)

• filter

• sieve

Multiple Choice

If I pour sand and water onto a filter, what will happen?

• water and sand will go through the filter

• sand will get caught in the filter, water will pass through

• both sand and water will get caught in the filter

Multiple Choice

A solution of salt and water was put over heat. What will happen next?

• The salt will evaporate

• the salt and water evaporate

• the water will evaporate

Multiple Choice

This type of paper allows liquid to pass through it. What tool is it?

• sieve

• filter

Multiple Choice

What tool is this?

• sieve

• filter

Multiple Choice

The best way to separate trail mix would be:

• filter

• by hand

• sieve

• evaporation

Multiple Choice

If I added 27 grams of salt to water and separated the solution with a hot plate, what amount of salt would be left behind?

• 20 grams

• 0 grams

• 27 grams

• 10 grams

Multiple Choice

To separate a mixture of salt and water what separation tool/method is used?

• Filter

• Sieve

• Magnet

• Evaporation

Multiple Choice

If you spilled nails in a sandbox, what separation tool/method could you use to clean out the sandbox so it would be safe for children to play in?

• Filter

• Screen

• Magnet

• Evaporation

Multiple Choice

You have a glass of salt and water, what is the best method to separate the salt out of the water?

Multiple Choice

What is electrolysis?

• The process of separating water and oil.
• The process of separating water and water.
• The process of separating the hydrogen atoms from oxygen atoms in H2O
• The process of separating sea-water and oil.

Multiple Choice

Separating mixtures based on boiling points.

• Desalination
• Distillation
• Decantation
• Condensation

Multiple Choice

What is the process of separating at which the components move at different rates?

• centrifugation
• chromatography
• heating
• decantation

Multiple Choice

An Element is made up of how many types of atoms?

• 12

• 36

• 58

• 1

Multiple Choice

Sam's mother is cooking breakfast in a cast-iron frying pan. If the pan is made only of iron, what can Sam conclude?

• The pan is a pure substance with the chemical symbol Ir.

• The pan is a pure substance with the chemical symbol I.

• The pan is a pure substance with the chemical symbol F.

• The pan is a pure substance with the chemical symbol Fe.

Multiple Choice

Which of the following is true of oxygen?

• Oxygen is an element because its most basic unit is a single type of atom

• Oxygen is a compound because its most basic unit is a single type of atom.

• Oxygen is a mixture because its most basic unit contains more than one particle.

• Oxygen is a compound because its most basic unit contains more than one type of particle.

Multiple Choice

Beatriz wants to make a mixture out of her bowl of blueberries. Which of the following would turn her bowl of blueberries into a mixture?

• adding more blueberries to the bowl

• adding raspberries to the bowl

• cutting up the blueberries

• mashing the blueberries

Multiple Choice

Humans absorb oxygen from the air they breathe in and exhale carbon dioxide gas, CO2. Carbon dioxide gas is

• an element made of carbon and oxygen atoms.

• a solution made of carbon and oxygen atoms.

• a compound of carbon and oxygen atoms.

• a mixture of carbon and oxygen atoms.

Multiple Choice

Mixtures are different than pure substances because mixtures-

• have lower boiling points

• can be separated physically

• are less dense than pure substances

• contain only one type of atom

Multiple Choice

Which answer correctly matches the diagram with the correct description?

• Q- Multiple compounds R-A single element S-An element and a compound T- A single compound

• Q- A single element, R- An element and a compound S-A single compound T-Multiple compounds

• Q- A single compound, R- A single element, S- Multiple compounds, T- An element and a compound

• Q- An element and a compound, R- a single compound, S- a single element, T- multiple compounds

Multiple Choice

In the diagrams provided, the circles of different colors represent the atoms of different elements. Which diagram represents a mixture?

• I

• II

• III

• IV

Multiple Choice

What is the relationship between molecules and atoms?

• Molecules are combinations of two or more atoms.

• Molecules are the parts that make up atoms

• Molecules are the gaseous parts of atoms

• Molecules are atoms that have a positive charge

Multiple Choice

What makes elements and compounds different from mixtures? Elements & compounds-

• have a constant composition (pure substances)

• are made of gases

• Will not change when heated

• conduct electric current

Multiple Choice

Label 3

• Beaker

• Conical Flask

• Boiling tube

• rounded bottom flask

Multiple Choice

Label part 1

• Thermometer

• Fractionating column

• condenser

Multiple Choice

Which of the following pairs of substances may best be separated through through fractional distillation

• sand and soil

• water and soil

• salt and sand

• water and alcohol

Multiple Choice

Water and alcohol are easily separated by distillation because of their

• different densities
• different boiling points
• different colours
• different melting points

Multiple Choice

• element
• compound
• mixture of elements
• mixture of compounds

Multiple Choice

• element
• compound
• mixture of elements and compounds
• mixture of compounds

Multiple Choice

• element
• compound
• mixture of elements
• mixture of compounds

Multiple Choice

• element
• compound
• mixture of elements
• mixture of compounds

Multiple Choice

This diagram represents...

• An element

• A molecule

• A compound

• A mixture of elements and compounds

Multiple Choice

Distillation uses two changes of state. what are they?

• Evaporation and condensation
• Evaporation and freezing
• melting and boiling
• sublimation and condensation

Multiple Choice

Separating mixtures based on boiling points.

• Desalination
• Distillation
• Decantation
• Condensation

Multiple Choice

A separation technique which uses a fractionating column to separate different liquid components in a mixture with different boiling points by heating mixture is called

• Fractional distillation
• filtration
• crystallization
• evaporation

Multiple Choice

Name the method of separation

• Fractional distillation

• Chromatography

• Condensation

• Evaporation

Multiple Choice

Which of the following pairs of substances may best be separated through distillation

•  sand and soil
• water and soil
• salt and sand
•  water and alcohol

Multiple Choice

Which one of the following would you use to separate sand from iron filings?

• a bar magnet

• filter paper

• chromatography paper

• alum