Changing state of matter is a ____________ change.
physical
100
What has mass and takes up space?
matter
200
A salad is an example of ____________________.
A heterogeneous mixture
200
What are the SI units for volume?
mL or cubic centimeters
200
Dissolving salt in water is a _______________ change.
physical
200
_____________________ hold atoms together in molecules.
Chemical bonds
300
A ________________ is made from 2 or more elements in a fixed ratio.
compound
300
How can you determine the volume of an irregularly shaped object?
Drop it into water in a graduated cylinder and measure the displacement of the water.
300
Burning wood in a campfire is a _____________ change.
chemical
300
What is a chemical formula?
A formula represents the elements in a compound and their ratios.
400
How do compounds and mixtures differ?
Compounds are chemically combined and are separated by chemical means. Mixtures are physically combined and are more easily separated by physical means.
400
How do we measure density?
mass/volume
400
Tarnishing of metal is a ______________ change.
chemical
400
What is the density of water?
1.0 gram/mL
500
What does it mean to be a Pure Substance? Give some examples.
A pure substance is only that substance and not combined with any other substance. Can be elements (oxygen) or compounds (water) or mixtures (salt in water).
500
In measuring volume, when would you use mL and when cubic centimeters?
Use mL for liquids and cc's for solids.
500
What is the primary difference between physical and chemical changes?
Physical changes do not produce new substances and can be separated using physical means. Chemical changes DO produce new substances and can only be separated by chemical means.
500
How can density be useful in identifying a substance?
If you can calculate the density of an object, you can compare it to the density of the substance in question. If density is the same, it is probably that substance.