The Periodic Table

By Leonard Calvin EdS

How was the Periodic Table created?Science is the search for

patterns in nature.In the 1800’s, many

scientists noticed patterns in the properties of different elements.

Look at the following elements, what patterns do you notice?Element Atomic # Atomic Radius

IonizationH 1 37 1300He 2 50 2380

Li 3 152 520Be 4 111 900B 5 88 800C 6 77 1100N 7 70 1400

Na 11 186 480Mg 12 160 700Al 13 143 600Si 14 117 800P 15 110 1010

Who discovered the patterns?

Dimitri Mendeleev Introduced a chart

summarizing the known properties of the elements to his students.

The chart resembles a calendar.

What did the original Periodic Table look like? Arranged the

original 60 elements in order by their increasing masses.

Left blanks because he predicted there were missing elements.

Ponder this:

Was the great organization of the periodic table invented by humans or discovered by humans? Explain.

What does the modern periodic table look like?

How is the PTE arranged?

by the type of element (substance)by the state of the element (solid, liquid,

or gas).the mass of the element.

How is the PTE organized?

GROUPS Vertical columns Similar properties

among the elements Have the same # of

electrons in outer shell (valence electrons)

Group 1-used in the making of soaps

Group 2-fire resistant

Group 11-precious metals

Group 17-tendency to form salts

Group 18-unreactive gases

More on how the PT is organized: PERIODS Horizontal rows Same number of

energy shells (where the electrons are)

Example: Period 2Li Be B C NO F and NeAll have 2 energy shells

Quick Review!

The PTE is an arrangement of the __________.

The elements are arranged in increasing _________& ___________.

The PTE has columns called________.

The PTE has rows called___________.

More review!

Groups Vertical ________on

the PTE. Have __________

properties because of the same number of __________ in the outer shell.

Those are called v_______ electrons

Periods Horizontal _______

on the PTE. All elements in the

same row have the same # of

e______ s______.

What’s in the rectangles?

Atomic Number-the number of electrons or protons

Symbol

Name

Atomic mass-protons plus neutrons

Practice reading the Periodic Table: What is the atomic

number? 8 What is the symbol? O What is the name of the

element? oxygen What is the atomic

mass? 15.99

Practice reading the Periodic Table? What is the atomic

number? 79 What is the symbol? Au What is the name of the

element? gold What is the atomic

mass? 196.97

Practice finding the # of electrons, protons and neutrons. How many protons? 11 How many

electrons? 11 How many

neutrons? 22.98 -11.00 11.98

Practice finding the # of electrons, protons and neutrons. How many protons? 8 How many

electrons? 8 How many

neutrons? 15.99 - 8.00 7.99

Practice finding the # of electrons, protons and neutrons. How many protons? 79 How many electrons? 79 How many neutrons? 196.97 - 79.00 117.97

How do you use the Periodic Table? From the

information on the periodic table, we can find the number of electrons, protons and neutrons.

Atomic number equals the protons or electrons.

Atomic mass minus the atomic number equals the number of neutrons.

Another way the periodic table is organized:

MetalsNon-MetalsMetalloids

Metals 85% of known elements Shiny Opaque Good conductors of

electricity Good conductors of heat Malleable-can be molded Ductile-can be drawn into

wires All but a few are solid at

room temperature (ex: Mercury)

Located to the left of zig zag

Neodymium

Non-Metals

On the right side of the zig zag line.

Dull Non-conductors of

heat & electricity Brittle, will shatter

when hammered At room temperature

some are solid, some are liquid, some are a gas

Reactive solids

Carbon

Metalloids

Between metals and non-metals, along zig zag line

Weak conductors of heat and electricity

Used for semi conductors (conducts w/ higher temps)

Take on the properties of their group

If closer to the metals-have more metal properties

If closer to non-metals-take on those properties

Germanium

Boron

Metal, non-metal or metalloid?

Leah has an element that is silvery gray, solid, brittle and is a semi conductor.

What is it?

Metal, non-metal or metalloid?

Tommy has an element that is shiny, solid, can be pulled into wire(ductile) and is a good conductor of heat and electricity.

What is it?

Metal, non-metal or metalloid?

Michael has an element that is a yellow solid that crumbles and does not conduct heat or electricity.

What is it?