NAME__________________________________DATE_______________PERIOD___________
Periodic Table Trends Activity
Introduction: The structure of the periodic table is such that elements with similar properties are aligned
vertically in columns called “groups” and one moves horizontally in a row is called “period”. Electrons, and
specifically valence electrons, are important in determining how an atom interacts with other atoms. The
elements in a group, also called “family” have similar properties because they have the same number of valence
electrons in similar configurations. The elements in the periodic table are divided into categories such as metal,
metalloid & nonmetal.
As you will learn in activity, there are various trends in properties such as electron affinity, ionization energy,
electron negativity and atomic radius as you go down a group or across a period. Ionization energy is the
amount of energy required for an atom to lose electrons and electron negativity is tendency of an atom to attract
other electrons.
Pre-Lab Questions:
1. What are groups? What are periods? _______________________________________________________
2. Define electron negativity and ionization energy________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
3. How do we organize different elements into a group?
__________________________________________________________________________________________
4. Mendeleev organized the periodic table by mass, how is the modern periodic table organized?___________
_________________________________________________________________________________________
Data:
Table 1: Atomic Radius Trend
Direction: Cut out the atom’s radius for the first 18 elements and glue it on this table.
IA
(1)
3
IIA
(2)
4
IIIA
(13)
5
IVA
(14)
6
VA
(15)
7
VIA
(16)
8
VIIA
(17)
9
VIIIA
(18)
10
Li
Be
B
C
N
O
F
Ne
11
12
13
14
15
16
17
18
Na
Mg
Al
Si
P
S
Cl
Ar
Group 2
Group 3
8
O
0.66
Atomic
Atomic
numbernumber
Symbol
Symbol
Atomic
radius
Atomic
radius (angstrom
Å)
Ionization (Å)
Table 2: Ionization Energy Trend
Directions: Create a line graph for ionization energy vs atomic number for the following elements
Group 2
Group 3
IA
(1)
3
Li
124
IIA
(2)
4
Be
215
IIIA
(13)
5
B
191
IVA
(14)
6
C
260
VA
(15)
7
N
335
VIA
(16)
8
O
314
VIIA
(17)
9
F
402
VIIIA
(18)
10
Ne
497
11
Na
119
12
Mg
176
13
Al
138
14
Si
188
15
P
242
16
S
239
17
Cl
299
18
Ar
363
8
O
314
500
Ionization Energy (kcal/mole)
400
300
200
100
Atomic
number
Atomic
number
Symbol
Symbol
Atomic energy
radius (kcal/mole)
(Å)
Ionization
Ionization energy
Analysis
1. What happens to the atomic radius as you go across a period (from left to right? And what happens
to the radius as you go down a group?
2. What happens to the ionization energy as you go across a period? And down a group?
3. What is the relationship between the atomic radius trend vs. the ionization energy trend?
Conclusion
1. Why do you think the atomic radius change as it does?
2. Why do you think the ionization energy change as it does?
3. Beside atomic radius and ionization energy what are some other trends?
ATOMIC RADIUS – cut and glue into table 1 in your data table