the Periodic Table

I am Dmitri Mendeleev!

I created the PERIODIC TABLE !

The periodic table is organized like a big grid.

Each element is placed in a specific location because of

its atomic structure.

What information can we find?

➤ Element➤ Name➤ Symbol➤ Atomic Mass➤ Atomic Number➤ Families

The periodic table is of ELEMENTS

Element Names:

WHERE DO THE NAMES OF ELEMENTS COME FROM?

➤ In Latin…• Gold = Aurum (Au is chemical symbol)• Silver = Argentum (Ag is chemical symbol)• Lead = Plumbum (Pb is chemical symbol)

➤ Einsteinium = Es

ATOMIC MASS

➤ The average mass of 1 atom of the element➤ The sum of the number of protons and neutrons in the nucleus of an atom

➤ Note: Electrons are not part of the atomic mass, because they are too light to add mass to an atom

ATOMIC NUMBER

➤ Elements of the periodic table are arranged by atomic number.➤ The number of protons in the nucleus of an atom.➤ If you know the number of protons, you can identify the element since the atomic number is equal to the number of protons.

IMPORTANT FORMULASAtomic Mass = Neutrons + Protons

Number of Neutrons = Atomic Mass - Atomic Number

Number of Neutrons = Atomic Mass - Proton Number

IONS➤ When an element is missing or has an extra electron.➤ Does not affect the mass of an element.➤ Will give an element either a negative or a positive charge.

Chemical Formulas

Elements, Compounds, and Mixtures

What is an ELEMENT?o A substance composed of a single kind of atom.

o Cannot be broken down into another substance by chemical or physical means.

What is a COMPOUND?o A substance in which two or more different elements are CHEMICALLY bonded together.

What is a MIXTURE?

o Two or more substances that are mixed together but are NOT chemically bonded.

➤Homogenous Mixture: A mixture where all

particles are evenly distributed throughout. You cannot pick out one type of particle from a homogenous mixture.➤ Example: Air, Iced-Tea (if mixed properly)

➤Heterogenous Mixture: A mixture where

all particles are not evenly distributed throughout. Different samples of mixture are not identical to one another. You can pick out one type of particle from a heterogenous mixture.➤ Example: Cereal and milk, pizza, blood, vegetable soup

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

MOLECULES/PARTICLES➤ Composed of a cluster of atoms and can be broken down into those atoms during a chemical change.➤ Can be made up of more than one type of element.

PURE SUBSTANCES➤ A substance that contains only 1 kind of particle/molecule.➤ A material that has consistent properties and constant composition.

➤ Example: Water, Tin, Sulfur, Table Salt, Sugar, Baking Soda

EXAMPLESHydrogen gas (H2) is a molecule, but not a

compound because it is made of only one

element.

Water (H20) can be called a molecule or a

compound because it is made of hydrogen

(H) and oxygen (O) atoms.

Chemical Formulas

Chemical Formulas are used to identify compounds using:

- Element Symbols - Numbers

The element symbols will never change from the periodic table (you can always use the periodic table to see which

symbol is for which element).

The numbers in chemical formulas are called subscripts. They tell you how many atoms of each element is in the compound. If there is no number as a subscript, there is ONE atom of this element.

For example:

COMPOUND ELEMENTS HOW MANY ATOMS?

Ag

F

1

2

Sr

Cl

1

2

F

Mo

O

2

1

2

Cd

Cl

1

2

C

H

N

O

P

3

8

1

5

1

Br

O

1

3

Al

F

Li

1

6

3

What would the following chemical formulas

be?

Organizing the Periodic

Table

Even though they skip some squares in between, all of the rows read

left to right. When you look at the periodic table, each row is called

a period

All of the elements in a periodhave the same number of atomic

orbitals.

For example, every element in the top row (the first period)

has one orbital for its electrons.

The periodic table also has a special name for its vertical columns. Each column is called

a group or family

The elements in each group have the same number of electrons in the

outer orbital.

Those outer electrons are also called valence electrons. They are the electrons involved in

chemical bonds with other elements.

Every element in the first column (group one) has one electron in its

outer shell. Every element in the second column (group two) has two

electrons in the outer shell.

There are exceptions to the order when you look at the transition

elements.

Hydrogen (H) and helium (He) are special elements. Hydrogen, in its neutral form,

does not have a neutron. There is only one electron and one proton.

Reactivity➤ All atoms want to be stable.

➤ Losing, sharing or gaining electrons is a way to become stable.

➤ When the outer shell is filled (in a Bohr diagram), elements are stable.

ReactivityThe number of

electrons indicates reactivity.

➤ If an element is missing one or two electrons in its valence shell (outermost shell in a Bohr diagram), it is considered reactive!

➤ Which Groups in the Periodic Table would have elements that are reactive?

GROUPS 1 + 2

Meet the families

FAMILIES: ALKALI METALS➤ First column (except Hydrogen)➤ Have one electron in their outermost level (1 valence electron)➤ Shiny, have consistency of clay, and are easily cut with a knife➤ The most reactive metals➤ React violently with water➤ Never found as free elements in nature, and are always bonded with another element

ALKALI METALS◆Most commonly

known Alkali metal:

–SODIUM

–When combined with Chlorine, makes Sodium Chloride…

–AKA Table Salt.

FAMILIES: ALKALINE EARTH METALS➤ Second column➤ They have 2 valence electrons➤ Solids➤ They are never found uncombined in nature➤ Not as reactive as Alkali Metals, they still bond easily due to their 2 valence electrons➤ Examples: Magnesium and Calcium

ALKALI EARTH METALS◆Magnesium

burns so actively in the air that it is

often used in flares.

◆Burns a brilliant, bright white.

FAMILIES: HALOGENS➤ Second last column➤ Can exist in solid, liquids or gases at room temperature depending on the element➤ Have 7 valence electrons which explains why they are the most active non-metals➤ Only need to gain 1 electron to fill their outermost energy level➤ They are never found free in nature

HALOGENS◆Common

Halogen uses:

–Iodine: Used to clean cuts and

in halogen lamps

FAMILIES: CHALCOGENS➤ Third last column, Group 16➤ Solids and gases➤ Have 6 valence electrons➤ Most elements share electrons with Chalcogens when forming compounds➤ This group varies the most in properties➤ Oxygen is the most abundant element in the Earth’s crust. It is extremely active and combineswith almost all elements

CHALCOGENS◆OXYGEN: We need

it to breathe and survive.

◆POLONIUM: Used to clean photography equipment.

FAMILIES: NOBLE GASES➤ Inert Gases➤ Last column of periodic table➤ Colourless gases that are extremely un-reactive, because their outermost energy level is full➤ They do not readily combine with other elements to formcompounds (thus called inert)➤ Examples: Helium, neon

NOBLE GASES◆Most commonly known noble gas:

–HELIUM

METALS◆ Constitute

more than 75% of all the elements.

◆ Concentrated on the left side and center of the table.

METALS◆Physical Properties of Metals:

–Shiny

–Generally a silver colour (except for gold and copper)

–Malleable

–Ductile

–Solid at room temperature (except Mercury)

–Conducts heat and electricity.

Examples of Metals

Chromium: Used in

making stainless

steel.

Barium: Used in

glassmaking

and in rat

poison

Scandium:

Used in high

intensity

lights. Thallium: Used in ant

killer and in treating

ringworm (in small,

controlled amounts)

NONMETALS◆ Constitute about 15% of the elements.

◆ Located on the far right side of the periodic table.

NONMETALS◆Physical Properties of Nonmetals:

– No lustre (shine)

– Brittle (not malleable or ductile)

– Non-conductors or insulators of heat

– Non-conductors or insulators of electricity (except graphite)

– Either solid or gas at room temperature (except bromine)

NonmetalsSulfur: Used in

making matches

and in

pyrotechnics

Neon: Used in light

signs and in lasers.

Fluorine: Used

in rocket fuel.

Radon: Naturally occurring

gas that can be a side

product of nuclear power

plants.

METALLOIDS◆ Constitute about 6% of the elements

◆ Located on the ‘staircase’ of the periodic table.

METALLOIDS◆Physical Properties of Metalloids:

–Have properties of both metals and nonmetals.

–All are solid at room temperature.

–Some have lustre (shine)

–Tend to behave like nonmetals (except in terms of electrical conductivity)

Metalloids

Boron: Used

in fighter

aircrafts and

in soaps.

Arsenic: Used in

the treatment of

cancer, but can be

poisonous in large

amounts.

Silicon: Used

in electronics

and automotive

parts.

The first 20 elements in the periodic table are the most common

elements in our universe

The most common element is carbon. All living things are

made of carbon.

GREAT WORK FOLKS!