the periodic table of the elements - palm beach state college

The Periodic Table of the Elements

All of the elements are composed of atoms.

An atom is the smallest part of an element which still retains the properties

of that element.

All matter is composed of elements.

All of the elements are listed on the Periodic Table by their Chemical Symbol

• The chemical symbol for every element is either one capital letter or one capital letter plus a small letter

For example:

C = carbon Ca = calcium Cl = chlorine Cr = chromium

Chemical Symbols

Chemical Symbols

• represent name of element

• consist of one to two letters and start with capital

1-Letter Symbols 2-Letter SymbolsC carbon Co cobaltN nitrogen Ca calciumF fluorine Al aluminum O oxygen Mg magnesium

3

Refer to Table 4.2 on Page 97

for list of the more common elements

and their symbols.

All of the elements on the Periodic Table are arranged in vertical columns called “Groups”, and in horizontal rows called

“Periods”.

All of the groups have numbers and they are

either “A” groups or “B” groups running from

left to right on the Periodic Table

Periodic Table of the Elements

Period

Group**

1

IA

1A

18

VIIIA

8A

1 1 H

1.008

2

IIA

2A

13

IIIA

3A

14

IVA

4A

15

VA

5A

16

VIA

6A

17

VIIA

7A

2 He 4.003

2 3

Li 6.941

4 Be 9.012

5 B

10.81

6 C

12.01

7

N 14.01

8 O

16.00

9 F

19.00

10 Ne 20.18

3 11

Na 22.99

12 Mg 24.31

3

IIIB

3B

4

IVB

4B

5

VB

5B

6

VIB

6B

7

VIIB

7B

8 9 10 11

IB

1B

12

IIB

2B

13 Al 26.98

14 Si

28.09

15

P 30.97

16 S

32.07

17 Cl

35.45

18 Ar 39.95

------- VIII ---

----

------- 8 -------

4 19

K 39.10

20 Ca 40.08

21 Sc 44.96

22 Ti

47.88

23 V

50.94

24 Cr 52.00

25 Mn 54.94

26 Fe 55.85

27 Co 58.47

28 Ni 58.69

29 Cu 63.55

30 Zn 65.39

31 Ga 69.72

32 Ge 72.59

33

As 74.92

34 Se 78.96

35 Br 79.90

36 Kr 83.80

5 37

Rb 85.47

38 Sr

87.62

39

Y 88.91

40 Zr

91.22

41 Nb 92.91

42 Mo 95.94

43 Tc (98)

44 Ru 101.1

45 Rh 102.9

46 Pd 106.4

47 Ag 107.9

48 Cd 112.4

49 In

114.8

50 Sn 118.7

51

Sb 121.8

52 Te 127.6

53 I

126.9

54 Xe 131.3

6 55 Cs 132.9

56 Ba 137.3

57 La* 138.9

72

Hf 178.5

73 Ta 180.9

74 W

183.9

75 Re 186.2

76 Os 190.2

77 Ir

190.2

78 Pt

195.1

79 Au 197.0

80 Hg 200.5

81 Tl

204.4

82 Pb 207.2

83

Bi 209.0

84 Po (210)

85 At (210)

86 Rn (222)

7

87 Fr

(223)

88 Ra (226)

89 Ac~ (227)

104 Rf (257)

105 Db (260)

106 Sg (263)

107 Bh (262)

108 Hs (265)

109 Mt (266)

110 ---

()

111 ---

()

112 ---

()

114

--- ()

116 ---

()

118 ---

()

Lanthanide

Series*

58 Ce 140.1

59

Pr 140.9

60 Nd 144.2

61

Pm (147)

62

Sm 150.4

63

Eu 152.0

64 Gd 157.3

65

Tb 158.9

66 Dy 162.5

67 Ho 164.9

68

Er 167.3

69

Tm

168.9

70

Yb 173.0

71

Lu 175.0

Actinide Series~

90

Th 232.0

91

Pa (231)

92 U

(238)

93 Np (237)

94

Pu (242)

95 Am (243)

96 Cm (247)

97

Bk (247)

98 Cf (249)

99 Es (254)

100 Fm (253)

101 Md (256)

102

No (254)

103 Lr (257)

Learning Check

Give the names of the elements with the following symbols:

A. P

B. Al

C. Mn

D. H

E. K

7

Solution

Give the names of the elements with the following symbols:

A. P = phosphorus

B. Al = aluminum

C. Mn = manganese

D. H = hydrogen

E. K = potassium

8

Groups

Columns of elements define element groups.

Elements within a group share several

common properties.

Periods

Rows of elements are called periods. The

period numbers increase as you go from top

to bottom on the periodic table. The number

of elements in a period increases as you

move down the periodic table.

Using grid coordinates (like a

checkerboard) each element can

be located on the Periodic Table.

Refer to Figure #4.2 on 0

Solution

Identify the element described by the following:

1. Group 7A, Period 4 bromine

2. Group 2A, Period 3 magnesium

3. Group 5A, Period 2 nitrogen

11

Learn the names of

the groups:

Ia = alkali metalsIIa = alkaline earth metalsAll “B” groups = Transition metalsVIIA = halogensVIIIA = noble (inert) gases

Classification of Groups

13

Page 101

Refer to Page 102

Identify each of the following elements as metal, nonmetal, or

metalloid.

A. sodium metal

B. chlorine nonmetal

C. silicon metalloid

D. iron metal

E. carbon nonmetal

14

Particles that are smaller than the atom are called subatomic particles.

• The three main subatomic particles that form an atom are protons, neutrons, and electrons. The center of the atom is called the nucleus.

Protons and neutrons make up the nucleus of

an atom.

STRUCTURE OF THE ATOM:

16

The atomic number

• is specific for each element.

• is the same for all atoms of an element.

• is equal to the number of protons in an atom.

• appears above the symbol of an element.

Atomic Number

11

Na

Atomic Number

Symbol

Si28.09

14 ----------Atomic number

-------- Mass number

An atom is the smallest part of an

element which still retains the

properties of that element.

An isotope is another form of an

element having a different number

of neutrons.

An element's or isotope's atomic number tells how many protons are in its atoms.

An element's or isotope's mass number tells how many protons and neutrons in its atoms.

P

N

e

Subatomic

Particle MassElectrical

Charge

1 +1

1 0

0 -1

Subatomic Particles in the Atom

21Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc.

See Page 108

4.5

• Protons have a positive electrical

charge, so they are often represented with the mark of a "+" sign.

• Neutrons have no electrical charge

23

Learning Check

Identify each statement as describing a

1) proton, 2) neutron, or 3) electron.

A. found outside the nucleus

B. has a positive charge

C. is neutral

D. found in the nucleus

Atomic Number

The atomic number

• is specific for each element

• is the same for all atoms of an element

• is equal to the number of protons in an atom

• appears above the symbol of an element in the Periodic

Table

Atomic Number

Symbol

24

11

Na

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc.

Every element, standing alone, in its neutral or uncombined state, MUST have

an overall electrical charge of ZERO.

• That means that the number of electrons (negatives) must equal the number of protons (positives).

Atoms Are Neutral

For neutral atoms, the net charge is zero.

number of protons = number of electrons

Aluminum has 13 protons and 13 electrons. The net

(overall) charge is zero.

13 protons (13+) + 13 electrons (13–) = 0


Composition of Some Atoms of

Different Elements


See Page 110

Table 4.6

Learning Check

28

Use the periodic table to fill in the atomic number, number of protons, and number of electrons for each of the following elements:

Element Atomic

Number

Protons Electrons

N

Zn

S


Solution

29

Use the periodic table to fill in the atomic number, number of protons, and number of electrons for each of the following elements:

Element Atomic

Number

Protons Electrons

N 7 7 7

Zn 30 30 30

S 16 16 16


• Elements: Each element has a fixed number of positively charged protons in its nucleus and an equal number of electrons orbiting the nucleus. For example, hydrogen (H) has one proton and one electron, but lead (Pb) has 82 protons and 82 electrons. There are about 115 known elements of which 82 are naturally abundant.

http://www.lbl.gov/Education/PeriodicTable/colortbl.PSD.gif

Study Tips: Protons and Neutrons

Number of protons = atomic number

Number of protons + neutrons = mass number

Number of neutrons = mass number – atomic number

Note: Mass number is given for specific isotopes only.


Learning Check

An atom of lead (Pb) has a mass number of 207.

A. How many protons are in the nucleus?

B. How many neutrons are in the nucleus?

C. How many electrons are in the atom?


Solution


A. How many protons are in the nucleus?

atomic number = 82; number protons = 82

B. How many neutrons are in the nucleus?

mass number – number protons = number neutrons

207 – 82 = 125 neutrons


Solution


C. How many electrons are in the atom?

An atom is neutral, which means that the

number of electrons is equal to the number of

protons. An atom of Pb has 82 protons and

82 electrons.


This would be the Periodic Table Representation for the

normal (stable) isotope of carbon:

C6

12

This indicates that the normal

isotope of carbon has 6 protons and

6 neutrons

Atoms of the same element can have different numbers of

neutrons; the different possible versions of each element are called

isotopes.

Isotopes

Isotopes

• are atoms of the same element

• have different mass numbers

• have same number of protons but different numbers of

neutrons


Atomic Symbols and Subatomic

Particles

38

Examples of number of subatomic particles for atoms:

Atomic symbol

16 31 65

O P Zn8 15 30

8 p+ 15 p+ 30 p+

8 n 16 n 35 n

8 e- 15 e- 30 e-


Atomic Symbols for Isotopes of

Magnesium

39

Mass Numbers

12

24Mg

12

25Mg

12

26Mg


Atomic Symbols for Isotopes of

Magnesium


Table 4.7

See Page 112

Learning Check

Naturally occurring carbon consists of three isotopes: 12C, 13C, and 14C. State the number of protons, neutrons, and

electrons in each of the following:

41

Isotope 12C 13C 14C

protons

neutrons

electrons


Solution

Naturally occurring carbon consists of three isotopes: 12C, 13C, and 14C. State the number of protons, neutrons, and

electrons in each of the following:

42

Isotope 12C 13C 14C

protons 6 6 6

neutrons 6 7 8

electrons 6 6 6


Which element does “X” represent in the following symbol ?

X80

35

A.) mercury B.) chlorine C.) scandium D.) bromine E.) selenium

Correct

answer

Nuclear NotationStandard nuclear notation shows

the chemical symbol, the mass number and the atomic number of

the isotope.

6C14

This notation represents the isotope of

carbon which has 8 neutrons, rather than

6 neutrons in the normal (stable)isotope

6C12

Normal

Isotope

See Page 102

See Page 114

All atoms of any given element have the

same mass. The mass of an element is the

number beneath its chemical symbol on

the periodic table.

It represents the average mass of the

isotopes that compose that element,

weighted according to the natural

abundance of each isotope of that

element.

The atomic mass of

chlorine is:

•1.) due to all the Cl

isotopes.

•2.) not a whole number.

•3.) the average of two isotopes: 35Cl and 37Cl.

See Page 113

Electrons spin and rotate around the outside of the nucleus.

Only a certain number of electrons can be in an energy level at the same time.

The octet rule says that atoms can only have a limited number of electrons in each electron shell.

Octet Rule:

The first (innermost) shell is

filled with 2 electrons.

All of the rest of the shells are

filled with 8 electrons

The octet rule:

Shell Number Number of electrons

1

2

3

4

5

2

8

8

8

8

(18)

(32)

Helium atom model

This helium (He) model displays two valence electrons

located in its outermost energy level.

Helium is a member of the noble gases and contains

two protons, neutrons, and electrons.

http://www.answers.com/topic/helium

http://www.answers.com/topic/noble-gas

http://www.answers.com/topic/proton

http://www.answers.com/topic/neutron

http://www.answers.com/topic/electron

http://en.wikipedia.org/wiki/Image:Atom.svg

http://en.wikipedia.org/wiki/Image:Atom.svg

The valence electrons are the electrons in the last shell or energy

level of an atom.

Elements in group IA have 1 valence electron. Elements in group IIA have 2 valence electrons.

For the “A” Groups on the Periodic Table, the Group Number indicates the number of valence electrons for every element in that group.

• The number of valence electrons of an element is determined by its periodic table group (vertical column) in which the element is categorized. FOR THE “A” GROUPS ONLY, the number of the group identifies how many valence electrons are contained within the elements listed under that particular column.

http://www.answers.com/topic/group-periodic-table

In the electron level arrangement for the first 18

elements

• electrons are placed in energy levels (1, 2, 3, etc.), beginning with the lowest energy level

• there is a maximum number in each energy level according to the octet rule.

Energy level Number of electrons

1 2 (up to He)

2 8 (up to Ne)

3 8 (up to Ar)

4 2 (up to Ca)

58

Example: 1

The electronic configurations of some of the elements are detailed below. How many valence electrons do the following

have?

(a) Al : 2, 8, 3 (Group 3A)

(b) Mg: 2, 8, 2 (Group 2A)

(c) Cl : 2, 8, 7 (Group 7A)

(d) Ca : 2, 8, 8, 2 (Group 2A)

Learning Check

Write the electron level arrangement for each:

60

N = 2, 5

Cl = 2, 8, 7

K = 2, 8, 8, 1

All atoms will tend to gain or lose

electrons in order to complete their outer

shell.

Metals will generally lose their outer

(valence) electrons to complete their

outer shell.

Nonmetals will tend to gain electrons to

complete their outer shell.

Metalloids may do either.

Recommended problems for chapter 4:

Page 104 . . . . # 4.7 through #4.12

Page 108 . . . . # 4.15 - #4.16

Page 111 . . . . # 4.23 - #4.30

Page 114 . . . . # 4.31 - #4.34

Page 115 . . . . # 4.35 - #4.36

Page 119 . . . . # 4.43 - #4.46

Page 130 . . . . # 4.87 - #4.90

Page 131 . . . . # 4.91 - #4.100

the periodic table of the elements - palm beach state college

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