Objectives

Objectives SWBAT analyze the importance of periodic law. SWBAT distinguish their family from the rest on the

periodic table.

Catalyst Get into groups and organize the elements in order of

increasing mass, and also line up the shading.

Today’s Agenda

Catalyst How is the periodic table organized? Intro Periodic Table Project Unlock the first secrets of the

periodic table Group work time Exit Question

First things first…

You are about to begin a journey to find thesecrets of the Periodic Table

The Periodic Table is a majestic tool used by

scientists all over the world

Are you ready?

Let’s go.

How is it organized?

Each group will receive a baggie of periodic table pieces

With your group, organize the pieces in a logical way

Be ready to explain HOW you organized the pieces

Now…

Organize the pieces in order of increasing atomic mass

Also, line them up according to shading

What’s missing?

GaGe

These elements were also missing when scientists were

putting the periodic table together!

The Periodic Table

Key Point #1: The periodic table organizes the elements into many different groups based on physical and chemical properties.

We will learn about the major ways to group the elements – by… Family Metals/metalloids/nonmetals Valence Electrons Atomic size Electronegativity

What does PERIODIC mean?

Key Point #2: Periodic means that there is some kind of pattern.

In the Periodic Table, there are numerous patterns What about in regular life? How could you group

the following items in different ways?

The Evolution of the Periodic Table

Just like atomic theory, the Periodic Table also has a long history

In the late 1790s, French scientist Antoine Lavoisier compiled a list of elements known at that time - only 23!

In the 1800s, scientists began discovering a ton of elements - up to 70!

Evolution Continued

New elements meant new data!

Scientists needed a way to organize everything!

John Newlands (1860s)

Arranged the Periodic Table by increasing ATOMIC MASS

Noticed patterns based on physical and chemical properties - repeated every 8th element

Law of Octaves

Newland’s Periodic TableLaw of Octaves

Mendeleev (1869)

Arranged elements by increasing ATOMIC MASS into columns based on chemical and physical properties

Left spaces for undiscovered elements

First to publish table

Mendeleev’s Periodic TableEMPTY SPACES!

Mosely (1913)

Arranged elements by increasing ATOMIC NUMBER

Some of Mendeleev’s elements in the wrong order

Periodic Law

Our Periodic Table – Thanks to Mosely

Periodic Law

Periodic Law is the statement that there is a periodic (patterned) repetition of chemical and physical properties of the elements when they are arranged in increasing atomic number

Periodic Table Review

1. Why is the periodic table called the “periodic” table?

2. How did Newlands organize the periodic table?

3. Who published the first periodic table?

4. Who developed periodic law?

Basic Terms to Know

Write these in your notes to remember!

Period – horizontal rows on periodic table

Family/Group – vertical columns on periodic table

Metals, Metalloids, and Nonmetals

Major FamiliesAlkali Metals

Alkaline Earth Metals

Transition Metals

Halogens

Noble Gases

LanthanidesActininides

H

Be B C N O F

He

Ce

Th

Alkali Metals

Alkali metals are very reactive – even with water!

Sodium + Water EXPLOSION!

Alkaline Earth Metals

Alkaline Earth metals are also very reactive Shiny solids that are harder than Alkali

metals Alkaline Earth Metal Spotlight: CALCIUM

Calcium is essential for human life, especially in maintaining bones and teeth

Found widely in nature combined with oxygen Abrasives in toothpaste and emery boards

Magnesium Demo!

Boron’s Group

Gallium is a silver metal that literally melts in your hand!

Don’t try this

yourself!

Carbon’s Group

Carbon is one of the most important elements on Earth! There is a whole branch of chemistry

dedicated to studying carbon – ORGANIC CHEMISTRY!

If you are a science major in college, you will most likely take Organic

Silicon is the second most abundant element on Earth! Use in computer chips and solar cells Found in quartz, sand, and glass

Nitrogen’s Group

Metals, nonmetals, and metalloids! Nitrogen, which you breathe, can

form some of the most explosive compounds known to man

Arsenic is a toxic substance that was used to treat some illnesses back in the day

Bismuth is used in fire sprinklers

Oxygen’s Group

Oxygen We must breathe oxygen to survive…

so it’s pretty important Reacts with some of the noble gases

Sulfur Hydrogen sulfide smells like rotten egg

Selenium Used in solar panels because it can

convert light into energy

Fluorine (really fluoride) is added to toothpaste

Chlorine gas is a deathly green gas that was first used as a form of chemical WARFARE in WWII

Halogens (Fluorine’s Group)

Noble Gases (Helium’s Group) Noble gases do not react with other

elements very often – they are already “happy” They can be called “inert” because

they don’t react Neon is used in neon lights Helium Voice!

Transition Metals

Conduct electricity Can form different ions (We’ll learn

more about ions later!) Many found in nature – found all

over the world (map on page 200) Uses

Found in alloys, wires, plastics, etc. Your body needs trace (small)

amounts many of them

Research Time

Pick your group’s familyStart researching info about your family

Chapter 7 in your book contains information about each family

Exit Question

1. Why is the periodic table called the “periodic” table?

2. What is your group’s family? List two characteristics of elements in your group’s family.

Homework: Periodic Table Assignment