1. Chapter 4 Elements, Compounds, and Mixtures … Oh My!

2. Section 1 – Elements Aa
A lot of this
will be
review

3. ELEMENTS
Pure substance that cannot be separated into simpler substances by physical or chemical means
Made up of atoms
Simplest form of matter
Each element contains only one type of particle
Ex: Silicon (Si), Helium (He), Gold (Au)

4. PROPERTIES
Each element can be identified by its unique set of characteristic properties.
Physical Properties:
boiling point, melting point, density,
Chemical Properties:
reactivity with acid, flammability

5. Classifying Elements.
Grouped into categories by the properties they share.
Elements in same group have shared properties.

7. 3 CATEGORIES

8. 3 CATEGORIES

9. 3 CATEGORIES

10. Section 2 – Compounds

11. COMPOUNDS
A pure substance composed of two or more elements that are chemically combined.
Elements combine by reacting, or undergoing a chemical change, with one another

12. A particle of a compound is a molecule
Two or more atoms join together to form molecules

14. PROPERTIES
Each compound has a unique set of properties just like elements.
Compounds have different properties
than the elements of which they are made.

15. Sodium Chloride (NaCl) – table salt
Sodium is a soft, silvery white metal that reacts violently with water
Sodium chloride is a white solid. It dissolves easily in water and is safe to eat
Chlorine is a poisonous, greenish yellow gas

16. Compounds can be broken down into elements or simpler compounds through chemical changes.
Energy can be added to break down a compound:
heat
electrical current

17. mercury
Heating the compound mercury(II) oxide breaks it down to the elements mercury and oxygen

20. Section 3 – Mixtures

21. SEPARATING MIXTURES By physical change – physically separating
Other examples: sorting, filtering, heating, cooling, distilling.

22. MIXTURES Made of two or more substances Properties of Mixtures
Any combination of elements, compounds, or both
Properties of Mixtures
NOT chemically combined
No chemical change occurs
No change to substances identity
Separated by physical means
Formed using any ratio of components (not set like in a compound)
Examples: salt water, steel, air, cereal, pizza, chicken soup, salad

23. And for separating BLOOD into its individual parts,
a centrifuge is used.
Sorry, couldn’t resist this close to Halloween.
By the way, what type of mixture is BLOOD

24. Two Kinds of Mixtures homogeneous mixture uniform composition
small particle evenly distributed
2. heterogeneous mixture
not evenly mixed
particles not uniformly distributed
easily separated physically

27. SOLUTIONS A mixture that appears to be a single substance.
It has an even distribution of particles throughout the mixture
Homogeneous mixture are solutions.

28. Solutions are formed by dissolving solute
into solvent
Solute – the substance that is dissolving
Solvent – the substance that the solute is dissolving in
The solute must be soluble (able to dissolve) in the solvent to make a solution.

29. PROPERTIES OF SOLUTIONS
Concentration – measure of the amount of solute dissolved in a solvent.
Concentrated – solution has more solute
Dilute – solution has less solute
Saturation – how much solute a solvent can hold
Unsaturated – solution can hold more solute
Saturated – solution has all the solute it can hold

30. It is the ability of the solute to dissolve in a solvent at a certain temperature

31. Solubility of Different Solids in Water
The solubility of most solids increase as the temperature gets higher. So, more solute can dissolve at higher temperatures. However, some solids, such as cerium sulfate, are less soluble at higher temperatures.

32. SUSPENSIONS
Particles are large enough to separate themselves from a solvent based on density.
Insoluble – particles not able to dissolve
Heterogeneous mixture
Examples: chicken soup, salad dressing.

33. COLLOIDS
Particles are small enough to mix with a solvent but not large enough to separate out.
Heterogeneous mixture
Properties of both solutions and suspensions
Spreads out like a solution
Does not dissolve like a suspension
Examples: JELL-O, fog, mayonnaise