Changes In Matter Pt1 (Physical/Chemical)- MG Flashcards
What is a physical change?
- It’s a transformation that doesn’t change the nature or the characteristic properties of matter. In other words, the molecules stay the same before and after the transformation.
- Physical changes don’t produce any new substances.
- Most of the time, physical changes are reversible. They can go back to the way they were before the transformation.
What are examples of physical change?
Phase change, shape change, and preparing or separating a mixture.
What’s it called when a phase change goes from solid to liquid?
Melting
What’s it called when a phase change goes from liquid to gas?
Vaporization
What’s it called when a phase change goes from gas to liquid?
Condensation
What’s it called when a phase change goes from liquid to solid?
Solidification/freezing
What’s it called when a phase change goes from solid to gas
Sublimation
What’s it called when a phase change goes from gas to solid
Deposition
Fill in the blank: Molecules ____ before and after a physical change.
Stay the same
Fill in the blank: Physical Changes don’t produce ___.
New substances
Fill in the blank: In a physical change, the characteristics of the substances involved ____.
Stay the same
Fill in the blank: Physical changes are generally ____.
Reversible
Match this statement with an example of a physical change: Mia makes jewelry by twisting copper wires.
Shape change
Match this statement with an example of a physical change: in the 19th century, gold miners sieved sediment from the Klondike River in the hope of finding gold nuggets.
Separation of a mixture
Match this statement with an example of a physical change: Jake adds food colouring to the icing for Kaylee’s bday cake
Preparation of a mixture
Match this statement with an example of a physical change: Aaralyn leaves a glass of water on the counter. After a few days, the water disappears.
Phase change
Does the following describe a physical change: Plants transform carbon dioxide into oxygen during photosynthesis.
No, this produces a new substance.
Does the following describe a physical change: Hanna cuts the cedar planks to make a bench.
Yes, it’s the same but in a different form.
What is a chemical change?
- A reaction that changes the nature of the substance (ex properties that are unique to the substance —> melting point, density, boiling point)
- New substance(s) are produced
- usually irreversible
- Opposite of a physical change
What are the 5 indicators of a chemical change?
Formation of a gas, formation of a precipitate (solid), change in colour, change in temperature, light is given off.
What is a “formation of a precipitate”?
A precipitate is formed when 2 liquids called “aqueous solutions” (water with dissolved substances inside) mix together to form a solid.
What are the TYPES of chemical changes?
- Synthesis
- Decomposition
- Oxidation
- Combustion
What is a “synthesis reaction”?
When 2 or more substances combine to make one new, more complex substance (ex. creation of water —> 2H+O2=H2O)
What is a “decomposition reaction”?
One substance breaks down into 2 or more simpler substances.
(Ex. Salt: NaCl —> Na + Cl)
What is an “oxidation reaction”?
A reaction between a substance and the oxygen in the air (usually with metals). Ex: Copper reacts with oxygen turning it green.
Where are most of the metals found on the periodic table?
Left-hand side.
What is a “combustion reaction”?
When a substance reacts with oxygen in the air and creates CARBON DIOXIDE AND WATER (ONLY), giving off a lot of heat, light and energy. (Only H2O and CO2 is released).
Match this statement with an example of a chemical change (5 indicators): Coal releases lots of heat as it burns.
Change in temperature
Match this statement with an example of a chemical change (5 indicators): When an antacid tablet is added to a glass of water, it frizzes.
Formation of a gas
Match this statement with an example of a chemical change (5 indicators): When a potassium iodide solution (Kl) is mixed with a lead nitrate solution (Pb(NO3)2), it creates a yellow substance called lead diiodide (Pbl2).
Formation of a precipitate
Match this statement with an example of a chemical change (5 indicators): Magnesium ribbon releases a bright light when heated.
Emission of light
Match this statement with an example of a chemical change (5 indicators): Copper powder starts off as orange but blackens as it is heated.
Colour change
What is “conservation of matter”?
In any physical or chemical transformation, the quantity of matter stays the same. In other words, the mass of the matter doesn’t change, because the atoms stay the same.
