1. The Periodic Table

2. Introduction to the Periodic Table
By 1830 fifty-five different elements had been isolated and named.
In 1869 Mendeleev arranged elements in order of increasing atomic mass and found that elements with similar properties fell into groups.
Moseley improved the periodic table by arranging the elements according to atomic number instead of atomic mass.

3. Modern Periodic Table
Contains seven period or rows of elements whose properties change gradually and eighteen groups or columns, each with a family of elements having similar properties.

4. Organization of Periodic Table
Groups 1 and 2 along with groups 13 to 18 are called the representative elements.
Groups 3 to 12 are called the transition elements.

5. Metal Has luster Conducts heat and electricity
Is malleable and ductile

6. Nonmetals
Are usually gases or brittle solids at room temperature

7. Metalloids
Shares properties with metals and nonmetals

8. Symbols
Are abbreviations usually based on the element’s name

9. Representative Elements
Groups 1 and 2 are active metals found in nature combined with other elements
Although hydrogen is placed in Group 1, it is not a metal and it shares properties with Groups 1 and 17

10. Alkali Metals Silvery solids with low densities and low melting points
They increase in reactivity from top to bottom of the periodic table

11. Alkaline Earth Metals Are denser, harder Have higher melting points
Are slightly less active than alkali metals in the same period

12. Groups 13 through 18
May contain metals, nonmetals, or metalloids in solid, liquid, or gas form.
The boron family elements in group 13 are all metals except boron, which is a metalloid; these elements are used in a variety of products.

13. Carbon Group
Elements are all metalloids or metals, except carbon itself
Carbon is found in all living things and exists in several forms.
Silicon and germanium are used in electronics as semiconductors.
Tin an lead are used in many products.

14. Nitrogen Group Contains nitrogen and phosphorus
Which are required by living things
Which are used in industry

15. Oxygen Family Contains oxygen and sulfur Which are essential for life
Used to manufacture many products

16. Halogen Group
Elements from salts with sodium and with other alkali metals

17. Noble Gases Rarely combine with other elements
They are often used in lighting and inflating balloons.

18. Transition Elements Groups 3 to 12 are metals
Most are combined with other elements in ores
The iron triad is composed of iron, cobalt, and nickel
They are used in many applications
Several transition elements can be used as catalysts, substance that make a reaction occur faster.

19. Inner Transition Elements
Are called lanthanides and actinides
The lanthanides are soft metals and were once thought to be rare.
All the actinides are radioactive; several are synthetic elements that do not occur naturally.
Dental materials are sometimes made of new composites, resins, and porcelains.

20. What does reactivity mean?
9F Reactivity in chemistry
What does reactivity mean?
Elements that are reactive readily take part in reactions with other chemicals.
But an element might react very quickly with one chemical and hardly at all with another. So is it reactive or not?
To compare the reactivity of different elements, we might see how easily they react with oxygen.
Some metals corrode in minutes out on the bench.
Others take longer to corrode, unless you heat them.

21. We can list metals in order of how quickly they react with oxygen.
9F The Gold Cup again?
We can list metals in order of how quickly they react with oxygen.
speed of reaction with oxygen
least reactive
most reactive
This ranking of metals according to reactivity is called the reactivity series.

22. What if we react different metals with acid?
9F Reaction of metals with acid
What if we react different metals with acid?
iron – the metal reacts slowly, producing a few bubbles
copper – no bubbles, no reaction with acid
lead – the metal reacts very slowly, producing very few bubbles
magnesium – the metal reacts quickly with the acid, producing lots of bubbles
sodium – the metal bursts into flames, a very strong reaction

23. reactivity series with
9F What about water?
We can also rank metals by their reaction with water.
Compare with the reactivity series for oxygen and acid.
reactivity series with
oxygen
acid
water
potassium
sodium magnesium zinc iron lead copper gold
potassium sodium magnesium zinc iron lead copper gold
The reactivity series is very useful. How can we learn it?

24. Chapter 4 Properties and Changes of Matter
Section 1 – Physical and Chemical Properties
Section 2 – Physical and Chemical Changes
Pages
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25. Physical Property
Characteristic that CAN be observed WITHOUT changing the composition of the substance.
Appearance – properties detected by senses
State - can be liquid, solid, or gas
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26. Physical Property cont…
Volume, mass, and density – measurements that describe physical properties
Melting point & boiling point are physical properties of a substance
Behavior – the way some substances behave
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27. Chemical Property
Characteristic that CANNOT be observed without altering the substance
Ability to burn
Tendency to rust
Reaction to other substances such as acids
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28. Physical Change
Form or appearance of matter changes, but composition stays the same
Shape can change, but substance does not
Example: Dissolving a solid into a liquid
Changing states through vaporization, condensation, sublimation, or deposition does not change the composition of matter.
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29. Chemical Change Results in a change in the substance’s composition
Color can change
Odor sometimes changes
Formation of gas or precipitation of a solid
Energy is gained or released during a chemical change
Chemical changes are NOT easily reversed.
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30. Big Difference Chemical changes DO alter the composition of substances
Physical changes DO NOT alter the composition of substances
Examples:
water freezes or evaporates – amount of matter stays the same -> physical change
Wood burns – ashes, smoke, and gases still total the same amount of matter -> chemical change.
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31. Law of Conservation of Mass
Particles of matter are not created or destroyed as the result of physical or chemical changes.
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