THE GREATEST TABLE ON EARTH!!!The Periodic Table of Elements

Periodic Table

Ever wondered: Why the Periodic Table is shaped the

way it is? Why is it called the Periodic Table? Why are there 2 disconnected rows? What information does it have?

Well today is your lucky day, because we are about to find out!

Periodic Table

The Periodic Table of the Elements shows every known type of atom.

It contains a large amount of information

Much of the information we can get just from the organization and shape of the periodic table

The Beginning The Periodic Table was first made in

1869 by a Russian named Dmitri Mendeleev

His table looked something like this:

What do you notice about his periodic table?

Mendeleev’s Periodic Table

Mendeleev ordered the elements by their atomic mass (he didn’t know protons existed yet)

He grouped those similar elements into columns He started a new column every

time the physical or chemical properties changed

Mendeleev left spaces for new, undiscovered elements and tried to predict their properties

Mendeleev’s Periodic Table As years went on, several elements

were discovered Their properties were nearly

identical to those that Mendeleev predicted

Eka-aluminium (Ea)

(Mendeleev’s Prediction)

Gallium (Ga)

(Discovered Element)

Atomic weight About 68 69.72

Density of solid 6.0 g/cm3 5.9 g/cm3

Melting point low 29.78oC

Valency 3 3

What Mendeleev’s Predictions Tell Us?

Mendeleev showed us there are patterns and trends to the elements

These patterns show us we can organize the elements by their properties

Atomic Number

The most obvious way that the periodic table is organized by increasing atomic number

However, this doesn’t explain why the elements are grouped the way they are

Atomic Mass

The atomic mass also increases (generally) as the atomic number increases

This, also, does not explain the element groupings

Periods

Rows on the periodic table are called periods

Periods

Elements are organized into periods based on where their electrons are

The outermost orbital filled by electrons determines what period an element is in If an elements outermost electrons are in the

1st orbital, the element is in the 1st period If an elements outermost electrons are in the

4th orbital, the element is in the 4th period

Groups The vertical columns of the periodic

table are organized by common physical and chemical properties

Why do you think these groups have similar properties?

Groups

Draw an atom of hydrogen, lithium, and sodium.

What do you notice about each of these atoms?

Groups Each atom has 1 electron in it’s outside

orbital Remember that electrons determine an

atoms behaviour Since each atom has the same

number of electrons in its outside orbital, they all behave the sameH Li Na

Groups

This outside orbital is the same for every atom in a group

This means that atoms in a group behave pretty much the same

Now let’s take a look at some notable groups

Group 1

Group 1 are called alkali metals They include the entire first column

(excluding hydrogen) They all:

Are soft, shiny, grey metals Are extremely reactive Have low densities, low hardness, and low

boiling points All burn with red, pink, or yellow colours

Group 2

Group 2 are called Alkali Earth Metals

Includes Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium

All are somewhat shiny, silvery-white, and are much harder than group 1

All make strong bases when mixed with water

Are about twice as dense as group 1

Group 17

Group 17 are called halogens Contains Fluorine, Chlorine, Bromine,

Iodine, and Astatine All are extremely reactive All are extremely dangerous to living

things (except iodine) All make acids with hydrogen All are vividly coloured

Group 18

Group 18 are called the Noble Gases

They include helium, neon, krypton, argon, xenon, and radon

Are all gases All do not react at all All glow with bright colours when

electricity is passed through them

Metals to Non-metals

The periodic table also organizes metals all the way to what are called non-metals

Metals are materials that: Have a shiny lustre Conduct electricity Conduct heat Are malleable

Transition Metals

The transition metals go from group 3 (scandium group) to group 12 (zinc group)

They are all conductors of electricity and heat

They all have a shiny lustre

Transition Metals

They are all malleable

They are all silver except for gold and copper

The only 3 magnetic elements are in the transition metals Iron Cobalt Nickel

Poor Metals

Poor metals are in group 13, 14, 15, and 16

Below the ‘staircase’ Are very malleable Very soft Poor electrical conductors Low boiling points

Non-metals

Non-metals do not conduct electricity or heat

Have a dull lustre (mostly) Are brittle Not malleable Exist as solids, liquids, and gasses Most are brightly coloured

The ‘Staircase’

Between the poor metals and the non-metals is a staircase

This line shows a separation between elements that act like metals and elements that don’t

Metalloids

Elements along the staircase are called metalloids

They act like metals and non-metals

Includes boron, silicon, germanium, arsenic, antimony, tellurium, and polonium

Metalloids Metalloids conduct some electricity

The hotter they are, the more conductive they are

Somewhat brittle Shiny lustre Make computers possible

Lanthanides & Actinides

The ‘disconnected’ rows of the periodic table are called the lanthanides and actinides

They are all radioactive

All are very reactiveLanthanides

Actinides

Blocks New information about how electrons work

has taught us about things called shells The periodic table is also organized by

which electron shell is furthest to the outside of an atom There are 4 shells

S – shaped like spheres P – shaped like dumbbells D – many shapes F – many shapes

Groups All atoms in the ‘s’ block have their outer most

electrons in the ‘s-shell’

All elements in the ‘d’ block have their outer most electrons in the ‘d-shell’

And so on…