bond day 2: #4. tek i7d – relate the chemical behavior of an element including bonding, to its...
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Bond
Day 2: #4
TEK I7D – relate the chemical behavior of an element including bonding, to its placement on the
periodic table Day 2: #4
Chemical Bond
Before there were bonds, there had to be elements!
Let’s review elements & the Periodic Table
hide
Periodic Table:Periods – horizontal rowsGroups or Families – vertical columns
Elements in the same group have similar chemical properties!
Period
Group
HI
D
E
Atomic number = # protons and it identifies the element!!!!!
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
D
E
2 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
D
E
2 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
D
E
2 3 4 5 6 7
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
D
E
2 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
D
E
2 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
D
E
2 3 4 5 6 7
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
D
E
2 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
D
E
2 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
Day 2: #4Question from TEA released TAKS test
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
Day 2: #4Question from TEA released TAKS test
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
Day 2: #4Question from TEA released TAKS test
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
Day 2: #4Question from TEA released TAKS test
5. According to the periodic table, which element most readily accepts electrons?
A Fluorine
B Nitrogen
C Arsenic
D Aluminum
Day 2: #4Question from TEA released TAKS test
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
Day 2: #4Question from TEA released TAKS test