1. Introduction to The Periodic Table

2. Why is the Periodic Table important to us?
The Periodic Table is the most useful tool to a chemist.
You get to use it on every test.
It organizes lots of information about all the known elements.

3. There are 92 naturally occurring elements arranged by atom size.
Periodic Table
There are 92 naturally occurring elements arranged by atom size.

4. The atoms are arranged by size from smallest (H) to largest.
Periodic table
The atoms are arranged by size from smallest (H) to largest.

5. Elements are arranged:
Vertically into Groups
We’ll learn later how this organization works.
Horizontally Into Periods

6. Hydrogen is the smallest atom.
Hydrogen has an atomic number of 1.
Hydrogen belongs to a family of its own.

7. Reading the Periodic Table
Each box on the Periodic Table stands for 1 of the elements. 6 C
CARBON 12
The atomic number for the element.
The symbol for the element.
The name of the element.
The atomic mass for the element.
If you have no trouble reading the above information off the Chart, click here to skip the sample problems.
We can get 4 pieces of information from that box.

8. Reading the Table: Symbols
Using your Periodic Table, answer these:
What is the chemical symbol for:
Sulfur?
Neon? S Ne
Answer all, and then click for the answers.

9. Reading the Table: Symbols
Using your Periodic Table, answer these:
What elements have these chemical symbols:
Ag?
Na?
Silver
Sodium
Answer all, and then click for the answers.

10. Reading the Table: Atomic Numbers
Using your Periodic Table, answer these:
What elements have these Atomic Numbers: 9?
56?
Fluorine
Barium
Answer all, and then click for the answers.

11. Let’s Review!
Every one of these elements is made of the same particles.
A Hydrogen proton is identical to Gold protons.
What makes atoms different is the number of protons.
The Atomic Number gives us the number of protons.

12. Atomic Number
The Atomic Number gives us the number of protons and electrons.
2. Sodium has an atomic number of 11. How many electrons does it have?
Helium has an atomic number of 2. How many protons does it have?
Use your copy of the Periodic Table for the rest of this activity. 11 2

13. Atomic Number
The Atomic Number gives us the number of protons and electrons.
What element has 15 protons?
2. What element has 92 electrons?
Let’s try the same problems in reverse.
Uranium
Phosphorus

14. Mass Number What element is it?
The Mass Number is the sum of the number of protons and the number of neutrons.
Mass Number = Protons + Neutrons
What is the mass number of an element that has 17 protons and 18 neutrons?
Hint: Use the formula above.
What element is it?
Hint: Look at the Periodic Table.
Chlorine 35

15. Mass Number
Many Periodic Tables will use the atomic mass or atomic weight instead of the mass number. I know it sounds confusing, but they are really the same thing as the mass number.
When using these Periodic Tables, you will have to round the atomic mass off to get the mass number. 8 O
OXYGEN
The atomic mass for oxygen is
We round off to 16. Thus 16 is the mass number of oxygen.

16. Finding the Number of Neutrons
The Mass Number is the sum of the number of protons and the number of neutrons.
Mass Number = Protons + Neutrons
Neutrons = Mass Number - Protons
2. How many neutrons does Aluminum have?
How many neutrons does Sulfur have? 14 16

17. Finding the Number of Neutrons
If you got those two questions right, click here to go to the next slide.
If you had trouble, click elsewhere on the slide to continue.
2. How many neutrons does Aluminum have? 14
Step 3: How many neutrons added to 13 would make 27?
Step 3: or what is 27 – 13?
Step 1: Find the Atomic Number and Mass.
Step 2: Calculate the number of protons.
The Answer is 14 neutrons.
Atomic Number – Atomic Mass - 27
Aluminum has 13 protons because that is the Atomic Number.

18. Review Questions Begin
Which element has the smallest atom?
Helium
Hydrogen
Oxygen
Nitrogen
Answer: Hydrogen (H)

19. Review Question # 2
Which element has an atomic number smaller than Aluminum?
Uranium
Iron (Fe)
Sodium (Na)
Chlorine
Answer: Sodium (Na)

20. Review Question # 3
Which element has an atomic number greater than Iron (Fe)?
Uranium
Lithium
Sodium (Na)
Chlorine
Answer: Uranium

21. Review Question # 4
Which element has a nucleus with 13 protons?
Calcium
Aluminum
Silicon
Iron
Answer: Aluminum

22. Review Question # 5
How many protons, electrons, and neutrons does Hydrogen have?
Answer:
Protons – 1
Electrons – 1
Neutrons - 0

23. Review Question # 6
How many protons, electrons, and neutrons does Phosphorus have?
Answer:
Protons – 15
Electrons – 15
Neutrons - 16

24. Review Question # 7
How many protons, electrons, and neutrons does Argon have?
Answer:
Protons – 18
Electrons – 18
Neutrons - 22

25. Review Question # 8
How many protons, electrons, and neutrons does Uranium have?
Answer:
Protons – 92
Electrons – 92
Neutrons - 146

26. “Constructing an Atom” PowerPoint.
Go back to the main page,
and
open the
“Constructing an Atom” PowerPoint.