Chapter 12, section 1
Electrons
and
Chemical Bonding
Bell Work 12-1-14
Plickers
1. When elements form mixtures, the elements
A. keep their original properties.
B. react to form a new substance with new
properties.
C. combine in a specific mass ratio.
D. always change their physical state.
Write the question and answer!
Student Learning Objectives:



SPI 0807.9.1- Recognize that all matter consists of atoms.
SPI 0807.9.4 - Differentiate between a mixture and a compound.
SPI 0807.9.9 - Use the periodic table to determine the properties of an
element.


Describe chemical bonding.
Identify the number of valence electrons in an atom.
TOC:
#63. Ch 12, section 1 Notes
#64. Valence Electrons
HW: Thursday- Element #11-20 Quiz
Friday- Word Wall Crossword Puzzle due
Element Quiz #2 on Thursday!
You need to know the Element Name, Symbol,
and Atomic # for Elements 11-20.
Electrons and Chemical Bonding
Cool Link!
Chemical bonding is the joining of atoms to form new
substances.
 An interaction that holds two atoms together is called a
chemical bond. When chemical bonds form, electrons are
shared or transferred.

The number of electrons in an atom can be
determined from the atomic number of the element.
 Electrons in an atom are organized in energy levels:
1st – 2; 2nd – 8; 3rd – 18.

Valence electrons are the number of electrons on the
outermost (last) energy level
 You can use the periodic table to determine the
number of valence electrons for atoms of some
elements

The number of electrons in the valence level of an
atom determine whether an atom will form bonds.
 Atoms that have 8 electrons in their valence level do
not usually form bonds. The outermost energy level is
considered to be full if it contains 8 electrons.


An atom that has fewer than 8 valence electrons is
more likely to form bonds than an atom that has 8
valence electrons. Atoms bond by gaining & losing
electrons or sharing electrons to have a filled
outermost energy level.
Move around the room!
Show Time!
1. Which of the following atoms do not usually form bonds?
Justify!
a. Calcium
b. Neon
c. Hydrogen
d. Oxygen
2. When bonding occurs, the joining of two atoms will form a
_______ _____________.
3. How can an atom that has 5 valence electrons achieve a full
set of valence electrons?
4. Identify the number of valence electrons in a barium atom.
Check!
1. Which of the following atoms do not usually form bonds?
a. Calcium
b. Neon
It’s a noble gas!
c. Hydrogen
d. Oxygen
2. When bonding occurs, the joining of two atoms will form
a new substance.
3. How can an atom that has 5 valence electrons achieve a full
set of valence electrons? They will share or gain 3
electrons.
4. Identify the number of valence electrons in a barium atom.
A barium atom has 2 valence electrons.
Valence Electrons
Color each Group:
1.Group 1 – red
2.Group 2 – blue
3.Group 13 – yellow
4.Group 14 – brown
5.Group 15 – orange
6.Group 16 – violet
7.Group 17 – green
8.Group 18 – light blue
Label the following groups:
 Alkali Metals
 Alkaline Earth Metal
 Transition Metals


Halogens
Noble Gases
Exit Ticket
Look at the model. How many valence electrons
are in the Nitrogen atom? Will Nitrogen
atoms form bond? Explain.