1. Properties of Atoms and the Periodic Table
Chapter 19
Properties of Atoms and the Periodic Table

2. 19.1 – Structure of the Atom Scientific Shorthand
Chemical Symbol – letter or pair of letters used to abbreviate the name of an element
One capital letter
Example: Hydrogen – H
One capital letter plus one or two lowercase letters
Example: Aluminum – Al
Example: Ununbium – Uub
Some symbols come from Latin words
Example: Argentum is Latin for Silver - Ag

4. Atomic Components
Atom – the smallest piece of matter that still retains the property of the element
Example: silver is made up of only silver atoms
Atoms are composed of 3 particles.
Protons – positively charged
Neutrons – neutral
Electrons – negatively charged

5. Nucleus
Small, positively-charged center of the atom
Where protons and neutrons are found
Surrounded by electron cloud
Electron cloud
The area around the nucleus where electrons are found
Electron’s have a small mass and move quickly around the nucleus
An electron cloud is a blur of all of the electrons within an atom

7. There is a worksheet to go with this
Meet the Elements Song
There is a worksheet to go with this

8. 19.2 – Masses of Atoms Atomic Number The number of protons in an atom.
Example: Oxygen – atomic number is 8, therefore it has 8 protons
The number of protons is equal to the number of electrons
Example: Oxygen – has 8 protons it has 8 electrons
Mass number
The sum of the number of protons and neutrons
Number of neutrons = mass number – atomic number

9. Isotope
Atoms of the same element that have different numbers of neutrons
Example: Carbon, Atomic number 6
Carbon-12 = 6 protons, 6 neutrons
Carbon-13 = 6 protons, 7 neutrons
Carbon-14 = 6 protons, 8 neutrons

10. Isotope
Symbol
Atomic Number
Mass Number
Protons
Electrons
Neutrons
Boron-11 B 5 11 6
Carbon-12 C 12
Oxygen-16 O 8 16
Sodium-23 Na 23
Copper-63 Cu 29 63 34

11. 19.3 – The Periodic Table Organizing the Elements
Periodic table – arrangement of elements based on increasing atomic number and changes in physical and chemical properties
Periodic Law – when arranged in this way, repeating patterns of physical and chemical properties are observed.
This is the basis for families of elements.

12. There are 3 major regions on the periodic table
Metals
Metalloids
Nonmetals

13. Metals
Exist as solids at room temperature
Shiny
Can be drawn into wires
Can be pounded into sheets
Good conductors of heat and electricity
Color – Gray, silver, yellow
Examples:
Iron
Zinc
Copper

14. Nonmetals
On the right side of the periodic table (except hydrogen)
Many are gases, but some are solids and one liquid (Br)
Brittle and dull
Poor conductors of heat and electricity
Colors – variety
Examples:
Oxygen
Bromine
Carbon

15. Metalloids
Located next to the stair step line
Also called semimetals
Have some properties of both metals and nonmetals
Shiny
Good conductor of electricity but not of heat
Color – gray or silver
Examples:
Boron
Silicon

16. Learning Check 1: Classify each element as a metal, nonmetal or metalloid
A.Mercury
B. Boron
C. Iodine
D. Aluminum
E. Neon
F. Barium
G. Germanium
Metal
Metalloid
Nonmetal
Metal
Nonmetal
Metal
Metalloid

17. Organizing the Periodic Table
Groups –
The vertical columns in the periodic table
Numbered 1 through 18
Elements in each group have similar properties
Example: Group 11 – copper, silver, and gold
Shiny metal
Good conductor of electricity and heat

18. Rows on the Periodic Table
Periods – horizontal rows of elements on the periodic table
The elements increase by 1 proton and 1 electron as you go from left to right in a period.
Their properties change in a predictable manner

19. Groups 18 1 1 13 14 15 16 17 2 2
Periods 3 3 4 5 6 7 8 9 10 11 12 4 5 6 7

20. There are 4 Major Groups
Group 1: Alkali metals (excludes hydrogen)
Group 2: Alkaline earth metals
Group 17: Halogens
Group 18: Noble Gases

21. Noble Gases
Alkali metals
Halogens
Alkaline Earth Metals

22. Group 1: Alkali Metals
“Alkali” means basic (opposite of acid)
These elements react with water to make bases
These are soft shiny metals that are gray in color.
Examples: Sodium, Lithium

23. Group 2: Alkaline Earth Metals
“Alkaline” also means basic
“Earth” because they are common in the earth’s crust
These elements are less reactive than the alkali metals but still react with water to produce bases.
Examples: Calcium, Magnesium

24. Group 17: Halogens
“halo” means salt
“gen” means to make or form
These elements react with metals to produce salts
Example: chlorine (Sodium chloride or calcium chloride are the salts produced)
Example: Fluorine (sodium fluoride is in toothpaste)

25. Group 18: Noble Gases
“Noble” like the kings and queens…too good to react with the common elements
Also called the inert gases because “inert” means not reactive.
These elements are highly stable and only form a few compounds.