All Things Chemical
A new solid that has formed.
Why is this question in the 'All Things Chemical' column? - due to a new substance being formed, which is evidence of a chemical reaction.
How do you define a physical property?
A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance.
What is the equation for density?
mass/volume
Follow up: What are the units connected?
grams/cubic centimeters or grams/millileter
You can write chemical reactions up as a word equation where one side of substances lead to the substances on the other side. What are substances called on each side of this equation?
Reactants -> Products
Which of the following is not an example of a physical property?
Flammability, Conductivity, Solubility
Flammability - this is a chemical property
Is density a:
chemical property
chemical change
physical property
physical change
And why?
Density is a physical property of a substance (because it is a property that can be observed without changing the identity of the substance)
What are three ways you know that a chemical reaction has occurred?
There is:
a temperature change, color change, a new substance has formed (solid, liquid, or gas), odor change, light or energy was created
Follow up question: Name one more not on your board.
In a lab, you notice that a liquid is forming bubbles while on the hot plate. Is this a chemical or physical change. Explain your choice.
This is most likely a physical change due to the liquid changing states of matter - this substance maintains it's identity, so therefore, does not go through a chemical change.
How did Archimedes discover that a crown was in fact NOT made out of gold?
He found the volume of the crown by putting it under water and seeing how much water was displaced. He compared the mass of that volume to a gold cube of the same volume and found that they were different masses.
Name 5 chemical changes you may see in every day life.
Fruit going bad/rotting. A fence rusting. Baking a cake. Using hydrogen peroxide on a wound. Digesting your food for energy. A camp fire/fireplace fire. Cars combusting gasoline to move. Etc.
Name 10 physical properties
Color, Taste, Odor, Length, Volume, Density, Mass, Shape, State of Matter, Melting Point, Boiling Point, Freezing Point, Solubility, Conductivity, Texture,
Why does it not matter if you have 100 pounds of wood or just a small square, when it comes to finding the density of wood?
A substance will have a density that is a constant for that substance regardless of how big or small it is. If its mass goes up, the volume would in the same ratio (and vice versa).