Atoms and the Periodic Table

1
Atoms and the Periodic Table

• Chapter 17
• Mrs. Chilton

2
Atoms

• Elements are made of particles called atoms
• Atoms are the smallest pieces of matter that
  contain all the properties of a specific element
• Each element contains only one type of atom

3
Essential Question

• How do we know what the atom looks like when no
  one has ever seen it?

4
Inside the Atom

• Atoms are made up of smaller particles
• These particles are found in different regions of
  the atom

5
Protons

• Positively charged particles found in nucleus of
  atom
• Have an electrical charge of 1
• Mass of 1 a.m.u.
• Composed of quarks

6
Neutrons

• Neutral particles found in nucleus of atom
• Have no electrical charge
• Mass of 1 a.m.u.
• Composed of quarks

7
Nucleus

• The nucleus is the positively charged dense core
  in the center of the atom
• Contains 99.9 of mass of atom
• Houses protons and neutrons

8
Electrons

• Negatively charged particles found in electron
  cloud
• Have an electrical charge of -1
• Constantly moving around outside nucleus
• Have essentially no mass

9
Electron Cloud

• Region around nucleus
• Houses electrons

10
Time to Make a Foldable!
11
Time to Make a Foldable!
12
Atomic Models

• Have been revised many times to explain new
  discoveries
• Democritus (4th century B.C.) thought the atom
  could not be split
• Theory was modified when subatomic particles were
  discovered

13
Newer Models

• Bohrs Model (1913) revised earlier thoughts
• Showed electrons moving in paths like planets
• Revised in 1925
• Now electrons in cloud

14
Valence Electrons

• Electrons in the outermost energy level of an
  electron are called valence electrons
• These are the electrons furthest from the nucleus

15
Symbols

• Elements are listed by their chemical symbols
• Symbols are usually either one capital letter
  like C for Carbon, or one capital and one
  lowercase letter like Ne for Neon

16
Periodic Table

• The periodic table gives much information we need
  to learn more about the atom of each element

17
Atomic Number

• Atomic number of protons in an atom
• Whole number shown on periodic table
• Periodic table is arranged by atomic number

18
Atomic Mass

• The average atomic mass is the number at the
  bottom of this square
• Found by averaging the natural abundances of its
  isotopes
• Mass p n0

19
Concept Map

• Complete this concept map

20
Atom Math
Atomic Number
Symbol
Element Name
Atomic Mass
21
Atom Math
Protons
Electrons
Protons
Neutrons
22
Practice
Zn
Lithium
Oxygen
30
8
3
15.999
65.39
6.941
8
30
3
35
8
4
8
3
30
n0 Mass - Atomic