Section 1.1 Why Do Atoms Combine?

1. 
Chemistry
Chapter 1 Section 1

2. Why Do
Atoms
Combine??
?

3. First, we
need to
know what
an atom is?

4. 4
Atomic Structure

5. Atomic Structure

6. Atomic Structure
All matter, even solids, contain mostly e m p t y
space.

7. Atomic Structure
All matter, even solids, contain mostly e m p t y
space.
How can this be?

8. Atomic Structure
All matter, even solids, contain mostly e m p t y
space.
How can this be?
Although there might be little or no space between
atoms, a lot of empty space lies within each atom.

9. Atomic Structure

10. Atomic Structure
At the center of every atom is a nucleus containing protons
and neutrons.

11. Atomic Structure
At the center of every atom is a nucleus containing protons
and neutrons.
The nucleus makes up most of the mass of an atom.

12. Atomic Structure
At the center of every atom is a nucleus containing protons
and neutrons.
The nucleus makes up most of the mass of an atom.
The rest of the atom is empty except for the atom’s electrons,
which are extremely small compared with the nucleus.

13. Atomic Structure
At the center of every atom is a nucleus containing protons
and neutrons.
The nucleus makes up most of the mass of an atom.
The rest of the atom is empty except for the atom’s electrons,
which are extremely small compared with the nucleus.
The exact location of an electron cannot be determined, the
electrons travel in an area around the nucleus called the
electron cloud.

14. Atomic Structure

15. Are you
ready
to be
amazed??

16. WOW

17. WOW
Atoms are extremely small.

18. WOW
Atoms are extremely small.
One hydrogen atom is approximately
5x10
-8
mm in diameter.

19. WOW
Atoms are extremely small.
One hydrogen atom is approximately
5x10
-8
mm in diameter.
Think about a 1 mm line. It would take
_______ hydrogen atoms lined up beside
each other to make a line as long as the
mark.

20. WOW
Atoms are extremely small.
One hydrogen atom is approximately
5x10
-8
mm in diameter.
Think about a 1 mm line. It would take
_______ hydrogen atoms lined up beside
each other to make a line as long as the
mark.
20 million!!!!

21. Electrons and Our Solar System

22. Electrons and our Solar System

23. Electrons and our Solar System
Plants orbit the sun, just as electrons orbit the
nucleus of an atom.

24. Electrons and our Solar System
Plants orbit the sun, just as electrons orbit the
nucleus of an atom.
Some differences between electrons and plants are:

25. Electrons and our Solar System
Plants orbit the sun, just as electrons orbit the
nucleus of an atom.
Some differences between electrons and plants are:
Planets do not have a charge, electrons are negatively
charged

26. Electrons and our Solar System
Plants orbit the sun, just as electrons orbit the
nucleus of an atom.
Some differences between electrons and plants are:
Planets do not have a charge, electrons are negatively
charged
Planets orbits are predictable, electron orbits are not
as predictable.

27. Element Structure
12

28. Element Structure
Each element has a
different atomic
structure and a different
number of protons,
neutrons, and electrons.
12

29. Element Structure
Each element has a
different atomic
structure and a different
number of protons,
neutrons, and electrons.
The number of protons
and electrons is always
the same for a neutral
atom.
12

30. Electron Energy

31. Electron Energy
All electrons in an atom are somewhere in the electron
cloud.

32. Electron Energy
All electrons in an atom are somewhere in the electron
cloud.
Some electrons are closer to the nucleus than others.

33. Electron Energy
All electrons in an atom are somewhere in the electron
cloud.
Some electrons are closer to the nucleus than others.
The different areas for an electron in an atom are called
energy levels.

34. Electron Energy
All electrons in an atom are somewhere in the electron
cloud.
Some electrons are closer to the nucleus than others.
The different areas for an electron in an atom are called
energy levels.
Each level represents a different amount of energy and
can hold a certain number of electrons.

35. Electron Energy
All electrons in an atom are somewhere in the electron
cloud.
Some electrons are closer to the nucleus than others.
The different areas for an electron in an atom are called
energy levels.
Each level represents a different amount of energy and
can hold a certain number of electrons.
The farther an energy level is from the nucleus, the more
electrons it can hold.

36. Energy Steps

37. Energy Steps
Text

38. Energy Steps
Text
Level Max. number of electrons
1st 2
2nd 8
3rd 18
4th 32

39. Energy Steps

40. Energy Steps
Energy Level 1 has the lowest amount of energy.

41. Energy Steps
Energy Level 1 has the lowest amount of energy.
Electrons furthest away have the most energy.

42. Energy Steps
Energy Level 1 has the lowest amount of energy.
Electrons furthest away have the most energy.
Electrons furthest away are the easiest to remove.

43. Energy Steps
Energy Level 1 has the lowest amount of energy.
Electrons furthest away have the most energy.
Electrons furthest away are the easiest to remove.
How many electrons can occupy an energy level?

44. Energy Steps
Energy Level 1 has the lowest amount of energy.
Electrons furthest away have the most energy.
Electrons furthest away are the easiest to remove.
How many electrons can occupy an energy level?
Use 2n
2
(n represents the energy level).

45. Magnets & Paper Clips

46. Magnets & Paper Clips
Removing electrons that are closer to the nucleus takes more
energy than removing ones that are further away.

47. Removing Part of the Balloon

48. Removing Part of the Balloon

49. Removing Part of the Balloon
What is being removed from
the balloons atoms?

50. Removing Part of the Balloon
What is being removed from
the balloons atoms?
Electrons

51. Removing Part of the Balloon
What is being removed from
the balloons atoms?
Electrons
From what energy level?

52. Removing Part of the Balloon
What is being removed from
the balloons atoms?
Electrons
From what energy level?
Highest energy level

53. Removing Part of the Balloon

54. Our Wonderful and Perfect
Periodic Table

55. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22

56. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22

57. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22

58. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22
Period 1

59. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22
Period 1

60. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22
Period 1
Period 2

61. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22
Period 1
Period 2

62. Our Wonderful and Perfect
Periodic Table
Horizontal Rows are called periods
22
Period 1
Period 2
Period 3

63. Our Wonderful and Perfect
Periodic Table

64. Our Wonderful and Perfect
Periodic Table
Remember that the number of protons and
electrons are the same in a neutral atom (which
is what is represented on the periodic table).

65. Our Wonderful and Perfect
Periodic Table
Remember that the number of protons and
electrons are the same in a neutral atom (which
is what is represented on the periodic table).
The number of electrons increases by one as
you move across the period.

66. Our Wonderful and Perfect
Periodic Table

67. Our Wonderful and Perfect
Periodic Table

68. Our Wonderful and Perfect
Periodic Table
A few things to notice....

69. Our Wonderful and Perfect
Periodic Table
A few things to notice....
Groups 3-12 are not pictured.

70. Our Wonderful and Perfect
Periodic Table
A few things to notice....
Groups 3-12 are not pictured.
Group 18 is complete, it is full. It has _____ electrons.

71. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

72. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

73. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

74. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

75. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

76. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

77. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

78. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

79. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26

80. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1

81. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2

82. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3

83. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3
Group
4

84. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3
Group
5
Group
4

85. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3
Group
5
Group
6
Group
4

86. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3
Group
5
Group
6
Group
7
Group
4

87. Our Wonderful and Perfect
Periodic Table
Vertical Rows are called Groups or Families
26
Group
1
Group
2
Group
3
Group
5
Group
6
Group
7
Group
4
Group
8

88. Our Wonderful and Perfect
Periodic Table
Hydrogen is usually
considered separately,
so the first element
family begins with
lithium and sodium in
the first column.
27

89. Our Wonderful and Perfect
Periodic Table

90. Our Wonderful and Perfect
Periodic Table
Human family members often have similar looks
and traits.

91. Our Wonderful and Perfect
Periodic Table
Human family members often have similar looks
and traits.
Also, members of element families have similar
properties, chemical properties, because they
have the same number of electrons in their outer
energy levels.

92. Our Wonderful and Perfect
Periodic Table
It was the repeating pattern of properties that
gave Russian chemist Dmitri Mendeleev the idea
for his first periodic table in 1869.

93. Why so Noble,
Group 18?

94. Why so Noble,
Group 18?

95. Why so Noble,
Group 18?
Noble Gases have energy levels that are complete. They have
8 electrons in their outer energy levels.

96. Why so Noble,
Group 18?
Noble Gases have energy levels that are complete. They have
8 electrons in their outer energy levels.
Do not combine well with other elements – originally thought
they would not combine at all, but they will on rare occasion.

97. Why so Noble,
Group 18?
Noble Gases have energy levels that are complete. They have
8 electrons in their outer energy levels.
Do not combine well with other elements – originally thought
they would not combine at all, but they will on rare occasion.
Because they are so stable they are used to protect filaments in
light bulbs.

98. Why so Noble,
Group 18?
Noble Gases have energy levels that are complete. They have
8 electrons in their outer energy levels.
Do not combine well with other elements – originally thought
they would not combine at all, but they will on rare occasion.
Because they are so stable they are used to protect filaments in
light bulbs.
Also used as to produce coloured lights in signs…electricity
causes the noble gases to emit a certain colour light.
Neon – orange/red; Argon – lavender; Helium – yellowish
white

99. Halogens From Halifax
(Group 17)

100. Halogens From Halifax
(Group 17)

101. Halogens From Halifax
(Group 17)

Halogens only need one more electron, so they are very
reactive.

102. Halogens From Halifax
(Group 17)

Halogens only need one more electron, so they are very
reactive.
Fluorine is the most reactive because the electrons are so
close to nucleus.

103. Halogens From Halifax
(Group 17)

Halogens only need one more electron, so they are very
reactive.
Fluorine is the most reactive because the electrons are so
close to nucleus.
Remember that when electrons are close to the nucleus,
there is a stronger pull from the protons.

104. Halogens From Halifax
(Group 17)

105. Halogens From Halifax
(Group 17)

106. Halogens From Halifax
(Group 17)

107. Halogens From Halifax
(Group 17)
The further you go down group 17, the
reactivities decrease.

108. Halogens From Halifax
(Group 17)
The further you go down group 17, the
reactivities decrease.
This is because there is more energy levels,
and so the electrons are further away from the
pull of the protons.

109. Halogens From Halifax
(Group 17)

110. Alkali Metals Have One Extra Petal
(Group 1)

111. Alkali Metals
Have One Extra Petal
(Group 1)

112. Alkali Metals
Have One Extra Petal
(Group 1)
Alkali Metals have one electron in outer most
energy level.

113. Alkali Metals
Have One Extra Petal
(Group 1)
Alkali Metals have one electron in outer most
energy level.
This electron will be removed when alkali metals
reacts.

114. Alkali Metals
Have One Extra Petal
(Group 1)
Alkali Metals have one electron in outer most
energy level.
This electron will be removed when alkali metals
reacts.
The easier it is to remove an electron, the more
reactive the atom is.

115. Alkali Metals
Have One Extra Petal
(Group 1)

116. Alkali Metals
Have One Extra Petal
(Group 1)
Reactivities increase as you go down
the group. Why?

117. Alkali Metals
Have One Extra Petal
(Group 1)
Reactivities increase as you go down
the group. Why?
Alkali metals want to give away one of
their electrons. That electron is further
away from the pull of the proton as
you move down group 1 in the
periodic table.

118. Electron Dot Diagrams

119. Electron Dot Diagrams
An electron dot diagram is the symbol
for the element surrounded by as many dots as
there are electrons in its outer energy level.

120. Electron Dot Diagrams
An electron dot diagram is the symbol
for the element surrounded by as many dots as
there are electrons in its outer energy level.
Only the outer energy level electrons are
shown because these are what determine how an
element can react.

121. Electron Dot Diagrams

122. Electron Dot Diagrams
Start by writing one dot on the top of the
element symbol

123. Electron Dot Diagrams
Start by writing one dot on the top of the
element symbol
Then work your way around, adding dots to the
right, bottom, and left.

124. Electron Dot Diagrams
Start by writing one dot on the top of the
element symbol
Then work your way around, adding dots to the
right, bottom, and left.
Add a fifth dot to the top to make a pair.

125. Electron Dot Diagrams
Start by writing one dot on the top of the
element symbol
Then work your way around, adding dots to the
right, bottom, and left.
Add a fifth dot to the top to make a pair.
Continue in this manner until you reach eight
dots to complete the level

126. Electron Dot Diagrams

127. Time for
some
REVIEW.

128. Question 1
Electrons are now known to swarm around
the nucleus of an atom in a configuration
known as the _______.
A. electron circle
B. electron cloud
C. electron configuration
D. electron swarm

129. Answer
The answer is B. The “cloud” includes all the
regions where an electron might be found.

130. Question 2
What information can you learn from this
diagram?

131. Answer
This image is an example of an electron dot
diagram. It tells you that nitrogen contains
five electrons in its outer energy level.

132. Question 3
The _______ an energy level is from the
nucleus, the _______ electrons it can hold.
A. closer, more
B. closer, less
C. farther, less
D. farther, more

133. Answer
The answer is D. The farthest shells contain
the greatest number of electrons.