Compounds, Mixtures, and Elements Topic 3 Oh My

Compounds, Mixtures, and Elements Topic 3 Oh My!!!

• http://dsc.discovery.com/videos/assignment-discovery-shorts-elements-compounds-and-mixtures.html

1. Three types of matter

A. Mixture

• made of two or more kinds of matter that are physically combined or mixed together.

• Example:
Salad

• Observations of mixtures

i. The properties of a mixture can vary because the composition of a mixture is not fixed.

• Other examples: Cinnamon and sugar, a bag of skittles? Hmmmm…..

ii. Can separate mixtures based on the physical properties of the matter

• Example: Salt water

• How do you separate the salt and the water?

• Gee, I can’t even see the salt in the water.

iii. Separate mixtures using:

Evaporation – separate solutions with heat

Filtering – remove visible solids in liquid

Special properties like magnetic- works on solids

• How would you separate this mixture?

• What will this separate?

• QUESTIONS

iv. Homogenous vs heterogeneous mixture

homogeneous: the same throughout

heterogeneous: parts are different from one another

• Homogeneous or heterogeneous

v. Three types of mixtures

Solutions, suspension, and colloids

• Solutions can be

• solids dissolved in liquids

• gases dissolved in liquids (such as carbonated water)

• gases in other gases and liquids in liquids.

• Making a solution

• Making Solutions

• 1. The solute is placed in the solvent and the solute slowly breaks into pieces.

• 2. The molecules of the solvent begin to move out of the way and they make room for the molecules of the solute. Example: The water has to make room for the sugar molecules.

• 3. The solute and solvent interact with each other until the concentration of the two substances is equal throughout the system.

• To be or not to be a mixture?

• Question: Are a bag of skittles a mixture?

• Design a procedure to answer the question. Your experiment must have the following:

• Question (1 pt)

• Hypothesis (1 pt)

• Procedure (2 pt)

• Must have one diagram

• Data Table (1 pt)

• Graph (1 pt)

• Conclusion (1 pt)

• Colloids a mixture consisting of tiny particles dispersed in a solid, liquid, or gas

• Mixture Summary

• No definite chemical composition

• Each type of matter keeps its properties

• Can be separated by physical means

• Return to its original “form”

• Three types of mixtures

• Solutions, colloids, suspension

• Video quiz

B. Compounds:

made up of atoms of two or more elements that are chemically combined. The elements are combined in a fixed ratio.

• Example:

Salt is made up of 1 atom of sodium and 1 atom of chlorine.

NaCl

Elements combine with other elements to become compounds.

Example: hydrogen and oxygen are both elements that are gases but when they combine they make WATER!!

Properties of compounds are very different than the properties of the elements that make them up.

Some elements may be very dangerous but when they combine to make a compound they are not.

• Harvesting Salt

• Poland Salt Mine

• Quick video activity

• Salt Homework

Compounds have physical and chemical properties that can be used to identify the compound.