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As you go through this study guide, please have the periodic table that you were given. You will be filling it in as you go.

The Periodic Table of

ElementsStudy Guide

Next Year…Next year you will be in 9th grade physical

science. The periodic chart you have received will be very useful to you next year. As you go through this study guide, you will be filling it in with information that will be very helpful next year. You will want to hold on to your chart.

Test on the atom unit next week

The information you will be studying today will be on the test next week. Go through each slide carefully. You can always go back to slides that you don’t fully understand. Taking notes as you go is a very good idea. For the test next week, you will be allowed a “cheat sheet” (a 3x5 card that you will create in class from your notes)

An atom refresherMatter is anything that takes up space and has

mass.All matter is made of atomsAtoms are the building blocks of matter, sort of

how bricks are the building blocks of houses.Elements are the alphabet to the language of

molecules.To make molecules, you must have elements. Elements are made of atoms. While the atoms

may have different weights and organization, they are all built in the same way.

You can’t just shove all of the electrons into the first orbit of an electron.

Electrons occupy something called shells or energy levels.

Only so many can be in any certain shell.

The number of shells an atom has relates to the period it is located in.

The group that an atom is in is related to how many electrons it has in its outer (valence) shell.

So let’s explore periods and groups in the next few slides.

Electrons have special rules….

Periodic TableThis table is a remarkable way to show the

manifold relationships between differing kinds of elements

The modern table was devised in 1869 by Dimitri Mendeleyev

He arranged the elements by weight and by their chemical properties

Periodic Table"...if all the elements be arranged in order

of their atomic weights a periodic repetition of properties is obtained." - Mendeleyev

The next slide shows a few of the elements from the table.

Periods and GroupsHorizontal rows in the periodic table are called

periods

Vertical columns are called groups

We will learn later why the elements can be arranged in this fashion based on the arrangements of the electrons outside the nucleus

Please note: Some Table of Elements show 18 groups, others show only 8 groups (the transition elements aren’t always considered to be in groups – you will see both ways in this study guide)

This shows 18 groups

This one shows 8 groups

Periods and Groups

Sizes of the atoms decrease as we move from left to right across a period (see the next slide)

This is due to the increasing number of protons in the nucleus, so the electrical attraction between the nucleus and the orbiting electrons gets stronger and pulls the electrons closer to the nucleus

Periods and GroupsWe can display the table to demonstrate other

properties as well

As you move from left to right across a period, the ability of the atom to attract another electron increases(See next slide)

This property is called electronegativity

•Each row is called a “period”

•The elements in each period have the same number of shells

Please make a note on your chart to help you remember

that whatever period an element is in, that is how

many shells it would have.

•Each column is called a “group”

•Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.

Except for He, it has 2 electrons

•The electrons in the outer shell are called “valence electrons”

Group 18 or 8 = Filled shells

Group 13 or 3= 3 electrons

•Transition Metals have slightly different rules for shells and valence electrons.

•This is something you will learn about in High School Chemistry.

• Helium is the exception in Group 8.

• Since it has just one shell, that shell can only fit 2 electrons instead of 8.

• It is in this group because all the elements have a full outer shell.

3

LiLithium

7

Protons = 3

Neutrons = 4

(7-3=4)

++

++++

--

--

--

Electrons = 3 Electrons = 3

2 in the 12 in the 1stst shell, 1 in the 2 shell, 1 in the 2ndnd shell shell

Review

Be sure to have all your answers on your study guide worksheet.

Remember, if you don’t

understand a section, you can always

go back and redo it.

Groups and Families

All the elements in a column have remarkably similar chemical properties

Some of the columns have been given special names to distinguish them (We call them families)

As you go through the families, very lightly color each family a different color. If you don’t have colored pencils with you, make a note to do it later when you do have them. (please…as you color the families, make sure it is very light and not so dark that you can’t see the numbers and symbol)

Alkalie FamilyThe first group (Group 1) is called the alkali metals

or Alkalai Family. They are the most chemically reactive of all the metals.

This group does not include Hydrogen, however. Hydrogen is in its own group.

Each element in this family has one valence electron.

Generally, if members of this family form an ion, they would have a +1 charge because of their tendency to give away one electron.

Please label the first group on your periodic table.

Alkaline-Earth Family

The second group is the alkaline-earth metals. They are also very chemically reactive, but not as much as the group in the Alkali family.

Each element in this family has two valence electrons.

Generally, if members of this family form an ion, they would have a +2 charge because of their tendency to give away two electrons.

Please label the second group on your periodic table.

Transition MetalsThe transition metals and aren’t considered a

family and aren’t named. (remember some charts will call these Groups 3-12)

Members of this group generally have 1, 2 or 3 valence electrons.

Generally, if members of this family form an ion, they would have a +1 or +2 or +3 charge because of their tendency to give away one, two, or three electrons.

Make a small note on your table to help you remember they are called the transition metals.

Boron FamilyGroup 3 is the Boron Family. (13 on some charts)

Each element in this family usually has three valence electrons.

Generally, if members of this family form an ion, they would have a +3 charge because of their tendency to give away three electrons.

Please label the this group on your periodic table.

Carbon FamilyGroup 4 is the Carbon Family. (14 on some charts)

Carbon is the backbone of all living things, Silicon is the backbone of computerized things.

Each element in this family usually has four valence electrons.

Generally, if members of this family form an ion, they would have a -4 charge because of their tendency to attract four electrons.

Please label the this group on your periodic table.

Nitrogen FamilyGroup 5 is the Nitrogen Family. (15 on some

charts)

Each element in this family usually has five valence electrons.

Generally, if members of this family form an ion, they would have a -3 charge because of their tendency to attract three electrons.

Please label the this group on your periodic table.

Oxygen FamilyGroup 6 is the Oxygen Family (16 on some charts)

Each element in this family usually has six valence electrons.

Generally, if members of this family form an ion, they would have a -2 charge because of their tendency to attract two electrons.

Please label the this group on your periodic table.

Halogen FamilyGroup 7 are the halogens (Salt Formers) Elements

in this group are the most reactive of the non-metals. (17 on some charts)

Each element in this family usually have seven valence electron.

Generally, if members of this family form an ion, they would have a -1 charge because of their tendency to attract one electron.

Elements in this family have a tendency to chemically react strongly with metals. The product of that chemical reaction is a salt.

Please label the this group on your periodic table.

Noble Gas FamilyGroup 8 (18 on some charts) are the noble gases and

are basically inert (inert means unable to chemically react with other elements)

Elements in this family all have filled valence shells.

Helium has just two electrons, and they fill its outer shell. The rest of the noble gases have 8 electrons in their outermost shells. (see the next slide)

These elements rarely or never form ions or join into chemical reactions.

Please label the this group on your periodic table.

Octet RuleThe Octet Rule states that atoms cannot have more

than 8 electrons in their outermost shell.

So that means that starting with the fourth shell, the atom flips any extra electrons to the previous shell.

For example, Krypton is in the fourth shell: - 2 electrons fill the first shell - 8 electrons fill the second shell

- 18 electrons fill the third shell (10 were flipped from the fourth shell)

- 8 electrons in the fourth shell

Electron Shell ExamplesShowing the Octet Rule

Zink (Zn) 2 electrons in the 1st shell8 electrons in the 2nd shell18 electrons in the 3rd shell2 electrons in the 4th shell

Bromine (Br)2 electrons in the 1st shell8 electrons in the 2nd shell18 electrons in the 3rd shell7 electrons in the 4th shell

The Rare Earth Elements (or Inner transition metals) are in periods 6 and 7, and are pulled out to make the Table more

compact.

Please label the Rare

Earth Elements

Thought QuestionsThink carefully about your answers

Why are there only two elements in the first period?

Why are there eight elements in the second and third periods?

Why do we jump to eighteen in the fourth period?

Why are the chemical properties of a group so similar?