Pure substances and Mixtures
Air contains nitrogen, oxygen, and carbon dioxide mixed together. Is air a pure substance or a mixture?
Mixture
The physical property of a substance that will dissolve in a liquid.
What is soluble/solubility
To separate a mixture of iron filings, sand, and salt, which tool should you use FIRST?
Magnet
Change state from gas to liquid.
Oil floats on water, but corn syrup sinks below water. Which of the three liquids is the MOST dense?
Corn Syrup
True or False: You can separate a pure substance into different parts using physical methods like filtering or magnets.
False
Describes a substance that has mixed completely with a liquid so that it is no longer visible.
A student tries to remove aluminum cans from a recycling pile using a magnet, but it fails. Why?
Aluminum is not magnetic
Does water GAIN heat energy or LOSE heat energy when it condenses from gas to liquid?
Lose heat energy
A plan says: "Use a mesh strainer with 1mm holes to remove dissolved salt from water." Why will this step fail?
Salt particles pass through the holes
True or False: Dissolving sugar in water creates a brand new substance.
False (it's a physical change)
Why can filter paper trap sand particles, but CANNOT trap dissolved salt particles?
Salt particles are too small (or dissolved)
Oil floats on top of water. Which physical property allows you to scoop the oil layer off the top?
Density
If 50 grams of ice melts inside a sealed bag, how many grams of liquid water will you have?
50 grams
An ordered set of steps written to solve a problem is called a ____ _____.
Name ONE example of a pure substance besides water.
Gold (or Oxygen, Salt, Sugar, Carbon Dioxide)
A special mixture where one substance dissolves completely in another and looks uniform.
Solution/Homogeneous mixture
What is the correct 2-step order to completely separate a mixture of sand, salt, and water?
Filter out the sand and then evaporate the water
Name one phase change where thermal energy is being removed
Condensation or freezing
Freezing point of pure water in degrees Celsius.
0°C
Has the same appearance and composition throughout.
What is a Homogenous mixture?
What is the formula for a solution?
(___+___= SOLUTION)
Solute+Solvent= Solution (vice versa)
A mixture is heated so that one substance evaporates. The vapour is collected and condenses into a liquid.
Describe the particle movement as it goes from a solid to a gas
The kinetic energy of the particles increase/speed up/move faster and/or the particles are spreading farther apart
This is Ms. Young's ___ year of teaching
3rd