STAAR Science Tutorial 10 TEK 8.5C: Periodic Table

Name: ____________________ Teacher: _______________ Pd. ___ Date: ________
STAAR Science Tutorial 10
TEK 8.5C: Periodic Table
TEK 8.5C: Interpret the arrangement of the Periodic Table, including groups
and periods, to explain how properties are used to classify
elements.
Elements and the Periodic Table
 An element is a substance that cannot be separated into simpler substances by
physical or chemical means. An element is already in its simplest form.
 The smallest piece of an element that still has the properties of that element is
called an atom.
 An element is a pure substance, containing only one kind of atom.
 The Periodic Table of Elements is a list of all the elements that have been
discovered and named, with each element listed in its own element square.
 Elements are represented on the Periodic Table by a one or two letter symbol, and
its name, atomic number and atomic mass.
The Periodic Table & Atomic Structure
 The elements are listed on the Periodic Table in atomic number order, starting at
the upper left corner and then moving from the left to right and top to bottom, just
as the words of a paragraph are read.
 The element’s atomic number is based on the number of protons in each atom of
that element. In electrically neutral atoms, the atomic number also represents the
number of electrons in each atom of that element.
 For example, the atomic number for neon (Ne) is 10, which means that each atom
of neon has 10 protons and 10 electrons. Magnesium (Mg) has an atomic number
of 12, which means it has 12 protons and 12 electrons.
 The element’s atomic mass as shown on the periodic table, is the average sum of
protons and neutrons in each atom of that element. It is the numerically larger,
non-whole number in the element square. (Note that the atomic mass for a single
particular atom is a whole number, because it is not an average of many different
atoms. There cannot be fractions of a proton or neutron in an actual atom.)
 The number of neutrons in an atom of a particular element can vary. These are
called isotopes of that element.
 Because the atomic mass is an average number, it is not a whole number, and has
to be rounded up or down to a whole number when used to calculate the number
of neutrons in the most common isotope of that element.
 To calculate the number of neutrons in the most common isotope of an element,
subtract the atomic number from the rounded atomic mass. For example, the
atomic mass of iron is 55.84, which rounds up to 56. Iron’s atomic number is 26.
The number of neutrons is thus 56 – 26 = 30.
1
Periods
1
1
H
3
 The horizontal (left-to-right) rows of the
periodic table are called periods. There are
seven periods in the periodic table.
2 Li
 Within each period, all elements have the
same number of occupied Bohr Model
electron “shells” (electron energy levels or
orbitals).
4
11
19
37
5 Rb
55
 The properties of the elements change
gradually as you move across each period.
For example, the atomic radius of each
element gets smaller as you move from left
to right within each period.
4
Be
12
3 Na Mg
K
20
87
3
21
Ca Sc
4
22
23
V
38
39
40
Y
Zr
56
5
Ti
Sr
6 Cs Ba
7 Fr
Period
2
41
7
8
24
25
2
Cr Mn F
42
72
73
74
Hf
Ta
W
105
106
88
104
Ra
Rf
57
89
43
4
Nb Mo Tc R
75
7
Re O
107
10
Db Sg Bh H
58
La Ce
Period Numbers
6
90
59
Pr
91
Ac Th Pa
60
6
Nd P
92
9
U
N
Groups or Families
 The vertical (up-and-down) columns indicate the 18 different groups or chemical
families of the periodic table, usually numbered 1 through 18, from left to right.
The elements within each group have the same general chemical properties and
the same number of valence electrons in the Bohr Model outer electron “shell.”
1
1
Group Numbers
H
3
2 Li
11
2
2
19
K
37
5 Rb
55
87
14
15
16
17
4
5
6
7
8
9
10
B
C
N
O
F
Ne
12
20
3
21
Ca Sc
4
22
23
V
38
39
40
Y
Zr
56
5
Ti
Sr
41
6
7
8
9
24
25
26
27
Cr Mn Fe Co
42
43
44
45
10
28
Ni
46
47
48
88
104
Ra
Rf
Db Practice
Sg Bh HsQuestions
Mt Uun Uuu Uub
110
32
33
34
31
74
109
18
Ar
30
W
108
78
Pt
17
Cl
29
73
107
77
Ir
16
O
Cu Zn Ga Ge As Se
Ta
106
76
15
P
12
72
105
75
14
Si
11
Nb Mo Tc Ru Rh Pd Ag Cd
Re Os
13
Al
Hf
6 Cs Ba
7 Fr
13
He
Be
3 Na Mg
4
18
1
79
80
Au Hg
111
49
In
50
51
52
36
Kr
53
54
I
Xe
Sn Sb Te
85
86
Group
At Rn
81
82
83
84
Tl
Pb
Bi
Po
112
35
Br
114
116
118
Uuq
Uuh
Uuo
1.
Each square in the periodic table represents a(n) ______________________.
2.
The numerically smaller
number
in each
element
square
La Cewhole
Pr Nd
Pm Sm
Eu Gd
Tb Dy
Ho is
Er Tm Yb Lu
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
89
90 _________________,
91
92
93
94
95
96
97 represents
98
99
100the101
102
103
the ________________
which
number
Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
of _______________________ in an atom of that element.
3.
The numerically larger non-whole number in each element square is
the ______________ -- ___________________, which represents the number
of ______________________ and _____________________ in an atom of that
element.
4.
In electrically neutral atoms, the number of protons is the same as the number
of ______________________.
5.
The horizontal (left-to-right) rows of elements are called
___________________, which indicate the number of
___________________________ (shells) in an atom of those elements.
6.
There are _____________ different periods.
7.
The physical and chemical properties of elements generally change gradually
across a ________________________.
8.
The vertical, up-and-down, columns of elements are called
___________________ or __________________.
9.
There are _______________ different groups.
10.
All of the elements in each column have similar ___________________
properties because they each have the same number of:
____________________________.