Periodic Table of Elements how it is arranged how it is used Science Standard: Use the periodic table as a model to predict the properties of elements based on patterns of the electrons in the outermost energy level of atoms Learning Target: Identify patterns in how the elements are arranged on the periodic table

How many protons are there? How many electrons are there? How many neutrons are there?

Why is the atomic mass not whole number?

What is the same and what is different about these atoms?

What is the same and what is different about these atoms? There are the same number or protons There are different numbers of neutrons These are all lithium atoms but they do not all weigh the same

Isotopes There are the same number or protons There are different numbers of neutrons These are all lithium atoms but they do not all weigh the same

What is the same and what is different about these atoms? What are these atoms?

Draw a model of a sodium atom

Valence Electrons There is one valence electron Electrons on the last energy shell (or ring) Can be no more than 8 electrons There is one valence electron

Determine the number of valence electrons for: Carbon - C

Determine the number of shells and the number of valence electrons for: Carbon - C 2 shells 4 valence electrons www.chem4kids.com

Ne Name the element. Number of shells ? Valence electrons ? Neon

Determine the number of shells and the number of valence electrons for: Name the element. Number of shells ? Valence electrons ?

H Name the element. Number of shells ? Valence electrons ? Hydrogen

Determine the number of shells and the number of valence electrons for: Name the element. Number of shells ? Valence electrons ?

Be Name the element. Number of shells ? Valence electrons ? Beryllium

Determine the number of shells and the number of valence electrons for: Name the element. Number of shells ? Valence electrons ?

S Name the element. Number of shells ? Valence electrons ? Sulfur

Periodic Table of Elements how it is arranged how it is used Science Standard: Use the periodic table as a model to predict the properties of elements based on patterns of the electrons in the outermost energy level of atoms Learning Target: Identify patterns in how the elements are arranged on the periodic table

Mendeleev's Original Table

Periodic Table Group: vertical column of elements (“family”) Period: horizontal row of elements

Periods Each row is called a “period” The elements in each period have the same number of shells 1st Period = 1 Shell 2nd Period = 2 Shells 3rd Period = 3 Shells 4th Period = 4 Shells www.chem4kids.com

Groups Group 8 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electrons Group 2 = 2 electrons Each column is called a “group” 3, 4, 5, 6, 7 Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons” www.chem4kids.com

Transition Metals Transition Metals have slightly different rules for shells and valence electrons. This is something you will learn about in High School Chemistry. www.chem4kids.com

Lewis Structures Find your element on the periodic table. Determine the number of valence electrons. This is how many electrons you will draw.

Lewis Structures Find out which group (column) your element is in. This will tell you the number of valence electrons your element has. You will only draw the valence electrons. www.chem4kids.com

Groups - Review Group 8 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electrons Group 2 = 2 electrons Each column is called a “group” 3, 4, 5, 6, 7 Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons” www.chem4kids.com

C Lewis Structures Write the element symbol. Carbon is in the 4th group, so it has 4 valence electrons. Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. C

C Lewis Structures Check your work. Using your periodic table, check that Carbon is in the 4th group. You should have 4 total electrons, or dots, drawn in for Carbon. C

C Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al C

H Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al H

P Lewis Structures On your worksheet, try these elements on your own: Ca Ar Cl Al P

Ca Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al Ca

Ar Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al Ar

Cl Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al Cl

Al Lewis Structures On your worksheet, try these elements on your own: P Ca Ar Cl Al Al

Periodic Groups and Trends

Periodic Table Group: vertical column of elements (“family”) Period: horizontal row of elements

Activity: get out your black and white copy of the periodic table.

On one side, color and label the metals, nonmetals, and metalloids. Another name for “metalloid” is “semi-metal”.

Color and label the groups/families of elements on the other side of your paper. Remember to create a legend. noble gases Transition metals alkali metals halogens alkaline earth metals lanthanides actinides

Coloring the Periodic Table Families Some images are from www.chem4kids.com www.middleschoolscience.com 2008

Families on the Periodic Table Elements on the periodic table can be grouped into families bases on their chemical properties. Each family has a specific name to differentiate it from the other families in the periodic table.

ALKALI METALS Group 1 Hydrogen is not a member, it is a non-metal 1 electron in the outer shell Soft and silvery metals Very reactive, esp. with water Conduct electricity Image: http://www.learner.org/interactives/periodic/groups2.html

ALKALINE EARTH METALS Group 2 2 electrons in the outer shell White and malleable Reactive, but less than Alkali metals Conduct electricity

TRANSITION METALS Groups in the middle Good conductors of heat and electricity. Some are used for jewelry. The transition metals are able to put up to 32 electrons in their second to last shell. Can bond with many elements in a variety of shapes.

BORON FAMILY Group 3 3 electrons in the outer shell Most are metals Boron is a metalloid

CARBON FAMILY Group 4 4 electrons in the outer shell Contains metals, metalloids, and a non-metal Carbon (C)

NITROGEN FAMILY Group 5 5 electrons in the outer shell Can share electrons to form compounds Contains metals, metalloids, and non-metals

OXYGEN FAMILY Group 6 6 electrons in the outer shell Contains metals, metalloids, and non-metals Reactive

Halogens Group 7 7 electrons in the outer shell All are non-metals Very reactive are often bonded with elements from Group 1

Noble Gases Group 8 Exist as gases Non-metals 8 electrons in the outer shell = Full Helium (He) has only 2 electrons in the outer shell = Full Not reactive with other elements

Rare Earth Metals Some are Radioactive The rare earths are silver, silvery-white, or gray metals. Conduct electricity

Write your answers on your handout. K Name the element. Number of shells ? Valence electrons ?

Write your answers on your handout. K Name the element. Number of shells ? Valence electrons ? Potassium 4 shells 1 valence electron

Potassium

Write your answers on your handout. He Name the element. Number of shells ? Valence electrons ?

Write your answers on your handout. He Name the element. Number of shells ? Valence electrons ? Helium 1st Period = 1 shell 8th Group = 2 valence electrons 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.