1. ATOMS AND THE PERIODIC TABLE chapter three

2. FOCUS ACTIVITY 1
METAL
USE
PROPERTY
Copper
Money
durable

3. ATOMIC THEORY - history
4TH CENTURY B.C.
Matter is made of tiny particles called ATOMS.
John DALTON
ELEMENTS are made
of particles called atoms.
ATOMS of the same
elements are alike.
ATOMS form molecules.
EARLY 1900’s
(1913)
ELECTRONS orbit like planets in the solar system.
MID 1900’s (after 1925)
Modern theory

4. ATOMIC THEORY - STRUCTURE MODEL OF THE ATOM
ELECTRON -
ENERGY LEVELS
NUCLEUS
PROTON +
NEUTRON
(NEUTRAL)

5. ATOMIC STRUCTURE ELECTRON LOCATION
Electrons are found in energy levels of an atom.
Electrons occupy the lowest energy level available.
Bohr’s Atom and Energy Levels

6. Energy Levels are like ladder rungs…
GAINING ENERGY
GOOD
BETTER

7. Energy Levels

8. ORBITALS – where the _____ are located within an energy level.
S orbital
(Like a sphere)
may contain up to 2 electrons
first energy level is an s orbital

9. 1s and 2s orbitals

10. P orbital (Like a dumbbell) may contain up to 2 electrons
second energy level may contain an s orbital and up to 3 p orbitals

11. Orbitals

12. _____ electrons are located in the outermost energy level of an atom.
They determine the chemical properties of an element.

13. 3.2 A TOUR OF THE PERIODIC TABLE
Properties of elements change in a regular pattern that the table helps to describe.
Periods –
Groups(families) -
Los Alamos National Laboratory: Periodic Table

14. Traditional Periodic Table
Los Alamos National Laboratory's Chemistry Division Presents a
Periodic Table of the Elements
Traditional Periodic Table

15. A Spiral Vision of the Periodic Table of the Elements

16. The number of protons in an atom determines an element’s location on the table. Los Alamos National Laboratory: Periodic Table

17. 6 C Carbon 12.001 ATOMIC NUMBER PROTONS SYMBOL NAME MASS + NEUTRONS
(and ELECTRONS too)
SYMBOL
NAME
PROTONS
+ NEUTRONS
MASS #
MASS

18. PROTONS AND NEUTRONS HAVE EQUAL MASS
PROTONS AND NEUTRONS HAVE EQUAL MASS. ELECTRONS ARE TINY – 1800 EQUAL ONE PROTON. 1 1
1800 1

19. MASS
ATOMIC NUMBER 17
protons _?_ electrons _?_
neutrons _?_ Cl

20. IONS are atoms that have lost or gained an ___.
ELECTRON GAINED =
NEGATIVE CHARGE
(-)
ELECTRON LOST =
POSITIVE CHARGE
(+)

21. Electron
transfer
Na+ Cl

22. A (+) CHARGED ION IS A ____.
TWO KINDS OF IONS:
A (+) CHARGED ION IS A ____.
A (-) CHARGED ION IS AN ___.
EXAMPLES:
LITHIUM
FLUORIDE

23. The atoms of an element always have the same number of protons. BUT…
The atoms of an element always have the same number of protons. BUT….. The atoms of an element may have different numbers of neutrons. This is an ISOTOPE!
Two carbon ISOTOPES:
CARBON 12 = 6 protons and 6 neutrons
CARBON 14 = 6 protons and 8 neutrons

24. The AVERAGE MASS of an ATOM
Why is the mass number not an even number?
Atoms of the same element exist with different numbers of neutrons.
This makes the mass of different atoms of the same element different.
The average mass is a weighted number so that more common isotopes have a greater affect on the average than rare isotopes.
What is an amu?
It is an “atomic mass unit”.
An amu is equivalent to the mass of 1/12 of a carbon-12 atom.

25. 3.3 FAMILIES OF ELEMENTS: HAVE THE SAME VALENCE NUMBER.
HAVE SIMILAR CHEMICAL AND PHYSICAL PROPERTIES.
A COLUMN OF ELEMENTS IS A FAMILY.

26. TWO MAJOR DIVISIONS
METALS
NONMETALS

27. GROUP ONE: ALKALI METALS
VERY REACTIVE
ONE VALENCE ELECTRON
                         
        

28. GROUP TWO: ALKALINE EARTH METALS
TWO VALENCE ELECTRONS

29. GROUP 3-12: TRANSITION METALS
MANY COMMON METALS
NOT AS REACTIVE AS OTHER METALS

30. GROUP 17: HALOGENS VERY REACTIVE FORM SALTS WITH ALKALI METALS
7 VALANCE ELECTRONS

31. GROUP 18: NOBLE GASES
INERT / UNREACTIVE
EIGHT VALENCE ELECTRONS

32. SYNTHETIC ELEMENTS They are man-made and radioactive.
They include all elements above #92, plus #43 and #61.

33. SEMICONDUCTORS (METALOIDS).
The elements that are between the metals and nonmetals are known as:
SEMICONDUCTORS (METALOIDS)
They may exhibit metallic and nonmetallic properties. B Si Ge As

34. 3.4 USING MOLES TO COUNT ATOMS
Some counting units:
Reams of paper
Dozens of eggs
Atomic mass units of protons and neutrons
Moles of atoms
A mole is the SI unit that describes the amount of a substance.
Avogadro’s constant is the number of particles in one mole which = x1023
molar mass is the mass in grams of one mol of a substance…it is equal to the average atomic number of an atom.

35. Chapter 3 Studying for the Test
Vocabulary
Parts of an atom
History
Element families
Using the periodic table
Metal vs. nonmetal