Download 5.1 Structure of the Periodic Table

Name
Date
5.1 Structure of the Periodic Table
1. Fill in the missing data on the table below.
Element
Protons
Neutrons
Ca
Electrons
Mass number
20
Atomic number
20
4
146
2
92
9
14
19
28
2. Using the periodic table in your textbook, find the name, atomic number, and average atomic mass of
the following elements.
Element
Name
Atomic number
Average atomic mass
K
Ag
Sn
Y
Answer the following question in complete sentences.
3. Why did Dmitri Mendeleev develop the periodic table?
4. What is the difference between the periodic table developed by Mendeleev and the one we use today?
Protons, Neutrons, and Electrons
The atomic number of an atom is the number of protons in each atom of that element.
Atomic Number = Proton Number
Because atoms are electrically neutral, the atomic number is also the number of electrons.
Atomic Number = Electron Number
The mass number tells you the number of protons and neutrons in an atom. By subtracting the atomic
number from the mass number, you can determine the number of neutrons.
Mass Number – Atomic Number = Neutrons
Use this information to complete the table.
Element
Atomic number
Mass number
Helium
2
4
Nitrogen
7
14
Carbon
6
12
Sodium
11
12
Iron
26
30
Copper
64
Silver
47
Lithium
3
Boron
11
Neon
20
Aluminum
27
Hydrogen
1
Electrons
29
7
9
12
Neutrons
61
Beryllium
Magnesium
Protons
4
5
10
13
24
0
Families of Elements
Use the periodic table in your book to fill in the missing data below.
Description
Family #
Number of electrons in
outer energy level
Halogens
Silicon
Alkaline earth Metals
Hydrogen
Aluminum
Nobel gases
Oxygen
Alkali metals
Using the periodic table, give the name of each of these elements and indicate whether it belongs to
the alkali metal or alkaline earth metal family.
Element
Be
Cs
Li
Ca
Element Name
Family Name