Pure Substances
Mixtures
Properties and Changes
Matter
Kinetic Molecular Theory
100
What is a pure substance?
A substance comprised of only ONE thing
100
What are the two main types of mixtures?
Heterogeneous & Homogeneous
100
A type of change that does NOT result in modifying the underlying chemical structure of substances.
Physical change
100
The particles that make up matter.
What are atoms?
100
The three* states of matter.
Solid, Liquid & a Gas
200
Does the following image depict a pure substance?
Why or why not?
Yes.
Same compound throughout.
200
What is the correct description of this substance?
Heterogeneous Mixture
200
What type of change is iron melting in a furnace?
Support your answer.
Physical Change
Change of State
200
Does the following depict a compound?
Why or why not?
No.
Only 1 element involved in the groups.
200
What happens to particles when they are frozen into a solid?
They are tightly packed and vibrate, however they cannot move.
300
What would you expect to find if you were measuring properties of a pure substance at different locations.
The same result.
They have uniform composition and properties.
300
What is the correct description of this substance?
Homogeneous Mixture
300
What are 3 indicators of chemical changes?
Change in color, Formation of gas, Formation of precipitate, Change in odor, Change in temperature
300
The three sub-atomic particles that atoms are made with.
Protons, Neutrons, Electrons
300
What state of matter is most likely displayed in this image?
Liquid
400
Would 14 Karat gold be considered a pure substance?
Explain.
No, it is a mixture.
400
A special category of mixture that has metallic properties.
What is an alloy?
400
If two substances are mixed together and produce bubbles, what do we KNOW about the chemical composition of the substances during this process?
They have changed.
400
What is the difference between a molecule, and a compound?
Molecules are groups of 2 or more ATOMS.
Compounds are groups of 2 or more ELEMENTS.
400
What happens to the particles of an ice cube when they are heated up?
The particles vibrate more quickly, and then break their bonds.
500
A substance does NOT contain a variable composition, but it DOES contain various types of atoms.
Is this a pure substance?
Explain.
Yes.
Compounds can be pure substances.
500
A homogenous mixture involving a solute(s) and solvent.
What is a solution?
500
If Blue food dye is mixed with water and changes its color, what type of change does this indicate?
Physical Change
The change in color is result of physical mixing not change in chemistry.
500
Define how hydrogen peroxide aligns with the terms: Molecule and Compound
Hydrogen peroxide is BOTH a molecule and a compound.
500
A sample of water is heated from 50°F to 75°F.
Describe the change experienced by these molecules at the molecular level.
Speeding up, but no change in state.