Pure Substances
What is a pure substance?
A pure substance is not mixed with any other substance or material, and cannot be separated.
What is a mixture?
Mixtures are two or more substances that are mixed together but not chemically joined.
What happens to particles when they are frozen?
They are tightly packed and vibrate, however they cannot move. (SOLID)
Give an example of a homogeneous mixture
salt water, sugar water, smooth peanut butter, milk are examples, among others
Give 1 example of a heterogeneous mixture.
Trail Mix, pizza, soil, rocky road ice cream
What are the two main types of pure substances?
Elements and Compounds
What are the two main types of mixtures?
Heterogeneous & Homogeneous
What is something that has all identical particles within its composition?
Pure Substance
Can you take apart a homogeneous mixture?
Sometimes yes, but not always. For example salt and water can be separated by evaporating the water. Each type of mixture has its own method of separation, depending on the parts it is made of.
It would be difficult to separate the ingredients in cake batter.
What is the difference between heterogeneous and homogeneous mixture?
Homogeneous looks the same throughout and you can't easily take the mixture apart. Heterogeneous can be taken apart and is very easy to tell the parts of the mixture.
The periodic table contains what?
Elements
What does homogeneous mean?
When a mixture does mix evenly-appears too look the same throughout.
(May LOOK like a pure substance but is NOT chemically bonded, just evenly mixed. Can be separated by physical means)
What happens to the particles of an ice cube when they are heated up? Give 2 characteristics.
They separate from each other (melt), and progressively move faster-away from each other and increase in space.
Give an example of a homogeneous mixture that you cannot physically see, but is all around us.
Air.
Give an example of a LIQUID hertergeneous mixture.
Oil and water, oil and vinegar
What is a compound? Give an example to support your answer.
A compound is a substance formed when two or more elements are chemically joined (Example: NaCl aka salt, H2O aka water, CO2 aka carbon dioxide)
What is a heterogeneous mixture?
A heterogeneous mixture DOES NOT mix evenly, and you can distinguish the different parts with your eyes. It can be separated by physical means
What would you need to do to increase the speed of the particles within matter?
Add heat
What two things do you need to create a homogeneous mixture? Be specific.
Solute and Solvent.
What causes oil and water to separate into a heterogeneous mixture?
density
Give three examples of an element.
Iron (Fe), Sodium (Na), Hydrogen (H) etc...
anything from the periodic table. Only the first 92 are natural, all others are man-made
What happens when I combine a solute and a solvent?
You get a solution.
The four states of matter in order of lowest energy to highest energy are:
Solid, Liquid, Gas & Plasma
Give an example of a homogeneous mixture that is not a liquid.
Metal alloys (mixtures), such as steel.
How can you get different compositions of a mixture, such as salt water?
By changing the amounts of the solvent and solute.