Bond
Day 2: #4
Chemical Bond
TEK I7D – relate the chemical
behavior of an element including
bonding, to its placement on the
periodic table
Day 2: #4
Before there were bonds, there
had to be elements!
Let’s review elements & the Periodic Table
hide
Periodic Table:
Periods – horizontal rows
Groups or Families – vertical columns
Elements in the same group have similar
chemical properties!
Group
Period
Atomic number = # protons and it
identifies the element!!!!!
HI
D
E
Valence Electrons – electrons involved in bonding;
all atoms “want” to have 8 or 0 valence electrons
to make them “happy and stable .”
The numbers in purple are the # of valence
electrons the atoms in those groups have.
1
8
HI
2
D
E
3 4 5 6 7
Metals (pink elements) usually have 1, 2, or 3
valence electrons.
In order to have 0 or 8 valence electrons, do
you think a metal will lose or gain valence
electrons?
1
8
HI
2
D
E
3 4 5 6 7
Metals will lose electrons and become positive ions!
Group 1 metals lose 1 ve- (which = 0 ve-)
Group 2 metals lose 2 ve- (which = 0 ve-)
Group 3 metals lose 3 ve- (which = 0 ve-)
Remember to think about the easiest way to reach 0 or 8!
1
8
HI
3 4 5 6 7
2 D
E
When an atom loses or gains ve- it becomes an ion!
Losing 1 ve- makes an ion with a +1 charge.
Losing 2 ve- makes an ion with a +2 charge.
Losing 3 ve- makes an ion with a +3 charge.
1
8
HI
2
D
E
3 4 5 6 7
Nonmetals (yellow elements) usually have 5,
6, 7, or 8 valence electrons.
In order to have 0 or 8 valence electrons, do
you think a nonmetal will lose or gain valence
electrons?
1
8
HI
2
D
E
3 4 5 6 7
Nonmetals will gain electrons and become negative ions!
Group 15 (5 ve-) nonmetals gain 3 ve- (which = 8 ve-)
Group 16 (6 ve-) nonmetals gain 2 ve- (which = 8 ve-)
Group 17 (7 ve-) nonmetals gain 1 ve- (which = 8 ve-)
Remember to think about the easiest way to reach 0 or 8!
1
8
HI
3 4 5 6 7
2 D
E
When an atom loses or gains ve- it becomes an ion!
Gaining 3 ve- makes an ion with a -3 charge.
Gaining 2 ve- makes an ion with a -2 charge.
Gaining 1 ve- makes an ion with a -1 charge.
1
8
HI
2
D
E
3 4 5 6 7
What about Group 18 (the Noble Gases)?
They already have 8 valence electrons so they are already
“happy” and stable. They are the “perfect” elements and are
considered unreactive!
1
8
HI
2
D
E
3 4 5 6 7
What are Chemical
Bonds?
• An attraction between two or
more atoms
• Interaction between
valence electrons
• All atoms need 0 or 8
valence electrons to
be “happy” or stable
Two Kinds of Bonds
• Ionic Bonds
-form ionic compounds
between metals and
nonmetals
-by losing /gaining electrons
• Covalent Bonds
-form covalent compounds
-by sharing electrons
1. An unidentified element has many of the same
physical and chemical properties as
magnesium and strontium but has a lower
atomic mass than either of these elements.
What is the most likely identity of this
element?
F Sodium
G Beryllium
H Calcium
J Rubidium
Question from TEA released TAKS test
Day 2: #4
2. The elements of which of these groups
on the periodic table are most resistant to
forming compounds?
A Group 1
B Group 9
C Group 14
D Group 18
Question from TEA released TAKS test
Day 2: #4
3. The elements from which of the following
groups are most likely to react with
potassium (K)?
F Group 2
G Group 7
H Group 13
J Group 17
Question from TEA released TAKS test
Day 2: #4
4. Which of the following groups contains
members with similar chemical reactivity?
A Li, Be, C
B Be, Mg, Sr
C Sc, Y, Zr
D C, N, O
Question from TEA released TAKS test
Day 2: #4
5.
According to the periodic table, which
element most readily accepts electrons?
A Fluorine
B Nitrogen
C Arsenic
D Aluminum
Question from TEA released TAKS test
Day 2: #4
6.
Elements in Group 16 of the periodic
table usually —
F form large molecules
G gain electrons when bonding
H act like metals
J solidify at room temperature
Question from TEA released TAKS test
Day 2: #4