An element is…
The simplest pure substance
One kind of material
Definite properties
Found on the Periodic Table of Elements

A compound is…
A pure substance
One kind of material
Definite properties
Two or more elements chemically combined
A molecule is the smallest particle of a compound that has all the properties of that compound
Water is a compound
H
2
O is a water molecule

A mixture is…
Matter
Two or more substances
Physically combined
NOT chemically combined

Heterogeneous Mixtures
Does not appear the same throughout
Least Mixed
Particles are large and easily separated
Homogeneous Mixtures
Appears to be the same throughout
Well mixed
Particles are small and not easily recognized

Heterogeneous
Mixtures
Homogeneous
Mixtures

A solution is…
A mixture
Homogeneous
Two or more substances
A single physical state

Solvent – That part of a solution which doing the dissolving
Solute – That part of a solution which is dissolved
Solute Solvent Solution
Gas
Gas
Gas
Liquid
Liquid
Solid
Solid
Gas
Liquid
Solid
Liquid
Solid
Liquid
Solid
Air
Soda Water
Air Filters
Antifreeze
Dental Filling
Ocean Water
Gold Jewelery

Law of Conservation of Mass
Atoms cannot be created nor destroyed
Mass cannot be created nor destroyed
Change results in arrangement of elements
Mass will remain constant
H = 1.0001 amu H
2
O = 17.9992 amu
H = 1.0001 amu
O = 15.999 amu

Object
Calculated
Mass
Measured
Mass
Notes
Discuss things like dissolved, in settled on bottom, cloudy, any other observations
Cup
Cup + 100 ml water
100 ml water
100 ml water + 10 g salt
100 ml water + 20 g salt
100 ml water + 30 g salt
100 ml water + 40 g salt
100 ml water + 50 g salt

Questions
1.
Did your calculated (predicted) results equal your measured results?
2.
Can you explain any differences?
3.
In which scenarios were you able to get the salt to dissolve and in which did you have salt remaining at the bottom of the cup?
4.
Did the amount of salt dissolved have any affect on your Conservation of Mass results?
Use the following data about a 2-L bottle of Mountain Dew to answer Questions 5 through 8.
Mass of Bottle = 55.6
Volume of Soda = 2000 ml
Mass of Sodium = 360 mg
Mass of Bottle + Soda = 2194 g
Mass of 2000 ml of Soda = 2138.4 g
Mass of Sugar = 276 g
5.
The density of water = 1 g/ml. How much should 591 ml of water weigh?
6.
How much (in grams) “stuff” is dissolved in the water to make it soda?
7.
How much should a bottle of soda weigh?
8.
Can you explain your observations and calculations?

An alloy is…
A mixture
A solution
Two metals or
A metal and a nonmetal

A suspension is…
A mixture
Heterogeneous
NOT a solution
Two or more substances
Particles large enough to settle and form a sediment

2 parts corn starch
1 part water
1 – 2 drops of food coloring
1. Put corn starch in the cup
2. Add the food coloring
3. Slowly add water a few drops at a time and stir

Our cornstarch goo (sometimes referred to as “oobleck” from the Dr.
Suess book) is what scientists call a “Non-Newtonian” liquid. Basically,
Sir Issac Newton stated individual liquids flow at consistent, predictable rates. As you likely discovered, cornstarch goo does NOT follow those rules – it can act almost like a solid, and them flow like a liquid. Technically speaking, the goo is a SUSPENSION, meaning that the grains of starch are not dissolved, they are just suspended and spread out in the water. If you let the goo sit for an while, the cornstarch would settle to the bottom of the bowl.
So why does this concoction act the way it does? Most of it has to do with pressure. The size, shape, and makeup of the cornstarch grains causes the cornstarch to “lock-up” and hold its shape when pressure is applied to it. People have filled small pools with oobleck and they are able to walk across the surface of it (as long as they move quickly.) As soon as they stop walking, they begin to sink.