Periodic Table chemistry form 4

7/28/2019 Periodic Table chemistry form 4

1/60

Periodic Table of Elements


2/60


3/60

goldsilver

heliumoxygen

mercury

hydrogen

sodium

nitrogen

niobium

neodymium

chlorine

carbon


4/60

Elements

Science has come

along way since

Aristotles theory of

Air, Water, Fire, andEarth.

Scientists have

identified 90 naturally

occurring elements,and created about 28

others.


5/60

Elements

The elements,

alone or in

combinations,make up our

bodies, our world,

our sun, and in

fact, the entireuniverse.


6/60

The most abundant element in the

earths crust is oxygen.


7/60

Periodic Table

The periodic table organizes the elements in aparticular way. A great deal of information about anelement can be gathered from its position in theperiod table.

For example, you can predict with reasonably goodaccuracy the physical and chemical properties ofthe element. You can also predict what otherelements a particular element will react withchemically.

Understanding the organization and plan of theperiodic table will help you obtain basic informationabout each of the 118 known elements.


8/60

Key to the Periodic Table

Elements are organized onthe table according to theiratomic number, usuallyfound near the top of the

square. The atomic number

refers to how manyprotons an atom of thatelement has.

For instance, hydrogenhas 1 proton, so itsatomic number is 1.

The atomic number isunique to that element.No two elements havethe same atomicnumber.


9/60

Whats in a square?

Different periodictables can includevarious bits of

information, butusually: atomic number

symbol

atomic mass

number of valenceelectrons

state of matter at roomtemperature.


10/60

Atomic Number

This refers to how

many protons an

atom of thatelement has.

No two elements,

have the same

number of protons.

Bohr Model of Hydrogen Atom

Wave Model


11/60

Atomic Mass

Atomic Mass refers

to the weight of

the atom. It is derived at by

adding the number

of protons with the

number ofneutrons.

HThis is a helium atom. Its atomic mass is 4

(protons plus neutrons).

What is its atomic number?


12/60

View CD-ROM Atoms and Elements


13/60

Atomic Mass and Isotopes While most atoms

have the same numberof protons andneutrons, some dont.

Some atoms havemore or less neutronsthan protons. Theseare called isotopes.

An atomic mass

number with a decimalis the total of thenumber of protons plusthe average number ofneutrons.


14/60

Atomic Mass Unit (AMU)

The unit of

measurement for

an atom is anAMU. It stands for

atomic mass unit.

One AMU is equal

to the mass of oneproton.


15/60

Atomic Mass Unit (AMU)

There are

6 X 1023 or

600,000,000,000,000,000,000,000 amus in

one gram.

(Remember that

electrons are 2000

times smaller than

one amu).


16/60

Symbols

All elements have

their own unique

symbol. It can consist of a

single capital letter,

or a capital letter

and one or twolower case letters.

CCarbon

Cu Copper


17/60

Common Elements and

Symbols


18/60

Valence Electrons

The number of valenceelectrons an atom hasmay also appear in a

square. Valence electrons are the

electrons in the outerenergy level of an atom.

These are the electronsthat are transferred orshared when atoms bondtogether.


19/60


20/60

Properties of Metals

Metals are good conductorsof heat and electricity.

Metals are shiny.

Metals are ductile (can bestretched into thin wires).

Metals are malleable (canbe pounded into thinsheets).

A chemical property ofmetal is its reaction withwater which results incorrosion.


21/60

Properties of Non-Metals

Non-metals are poorconductors of heat andelectricity.

Non-metals are notductile or malleable.

Solid non-metals arebrittle and breakeasily.

They are dull.

Many non-metals aregases.

Sulfur


22/60


23/60


24/60


25/60

Families Periods Columns of elements are

called groups or families.

Elements in each family

have similar but not

identical properties.

For example, lithium (Li),

sodium (Na), potassium

(K), and other members of

family IA are all soft,white, shiny metals.

All elements in a family

have the same number of

valence electrons.

Each horizontal row ofelements is called aperiod.

The elements in a period

are not alike in properties. In fact, the properties

change greatly acrosseven given row.

The first element in aperiod is always anextremely active solid. Thelast element in a period, isalways an inactive gas.


26/60


27/60


28/60


29/60


30/60


31/60


32/60


33/60


34/60


35/60


36/60


37/60


38/60

Hydrogen

The hydrogen square sits atop Family

AI, but it is not a member of that family.

Hydrogen is in a class of its own. Its a gas at room temperature.

It has one proton and one electron in its

one and only energy level.

Hydrogen only needs 2 electrons to fill

up its valence shell.


39/60

Alkali Metals

The alkali family is found inthe first column of theperiodic table.

Atoms of the alkali metalshave a single electron intheir outermost level, inother words, 1 valenceelectron.

They are shiny, have theconsistency of clay, and areeasily cut with a knife.


40/60


41/60

What does it mean to be

reactive?

We will be describing elements according to theirreactivity.

Elements that are reactive bond easily with otherelements to make compounds.

Some elements are only found in nature bondedwith other elements.

What makes an element reactive? An incomplete valence electron level.

All atoms (except hydrogen) want to have 8 electrons intheir very outermost energy level (This is called the rule ofoctet.)

Atoms bond until this level is complete. Atoms with fewvalence electrons lose them during bonding. Atoms with 6,7, or 8 valence electrons gain electrons during bonding.


42/60

5


43/60


44/60


45/60


46/60

Transition Metals

Transition Elementsinclude those elementsin the B families.

These are the metalsyou are probably mostfamiliar: copper, tin,zinc, iron, nickel, gold,and silver.

They are goodconductors of heat andelectricity.


47/60

Transition Metals

The compounds of transition metals are usuallybrightly colored and are often used to color paints.

Transition elements have 1 or 2 valence electrons,which they lose when they form bonds with otheratoms. Some transition elements can lose electronsin their next-to-outermost level.


48/60

Transition Elements

Transition elementshave propertiessimilar to one another and to other

metals, but their properties do not fit inwith those of any other family.

Many transition metals combine

chemically with oxygen to formcompounds called oxides.


49/60

Boron Family

The Boron Family isnamed after the firstelement in the family.

Atoms in this family have 3valence electrons.

This family includes ametalloid (boron), and therest are metals.

This family includes themost abundant metal in theearths crust (aluminum).


50/60

Carbon Family

Atoms of this family have4 valence electrons.

This family includes anon-metal (carbon),metalloids, and metals.

The element carbon iscalled the basis of life.There is an entire branchof chemistry devoted tocarbon compounds calledorganic chemistry.


51/60

Nitrogen Family

The nitrogen family is namedafter the element that makesup 78% of our atmosphere.

This family includes non-metals, metalloids, andmetals.

Atoms in the nitrogen familyhave 5 valence electrons.

They tend to share electronswhen they bond.

Other elements in this familyare phosphorus, arsenic,antimony, and bismuth.


52/60

Oxygen Family

Atoms of this family have 6

valence electrons.

Most elements in this family

share electrons whenforming compounds.

Oxygen is the most

abundant element in the

earths crust. It is extremelyactive and combines with

almost all elements.


53/60

Halogen Family

The elements in this

family are fluorine,

chlorine, bromine,

iodine, and astatine. Halogens have 7

valence electrons, which

explains why they are

the most active non-metals. They are never

found free in nature.

Halogen atoms only need

to gain 1 electron to fill theiroutermost energy level.

They react with alkali

metals to form salts.


54/60

Noble Gases

Noble Gasesare colorless gases that are extremely un-reactive.

One important property of the noble gases is their inactivity.They are inactive because their outermost energy level is full.

Because they do not readily combine with other elements toform compounds, the noble gases are called inert.

The family of noble gases includes helium, neon, argon,krypton, xenon, and radon.

All the noble gases are found in small amounts in the earth'satmosphere.


55/60

Rare Earth Elements

The thirty rare earthelements are composedof the lanthanide andactinide series.

One element of thelanthanide series andmost of the elements inthe actinide series arecalled trans-uranium,

which means synthetic orman-made.


56/60

Mendeleev

In 1869,Dmitri IvanovitchMendelev created the first accepted

version of the periodic table.

He grouped elements according totheir atomic mass, and as he did, he

found that the families had similar

chemical properties.

Blank spaces were left open to addthe new elements he predicted

would occur.


57/60

Matter

All matter is composed of atoms and groups

of atoms bonded together, called molecules.

Substances that are made from one type of

atom only are called pure substances.

Substances that are made from more than one

type of atom bonded together are called

compounds.

Compounds that are combined physically, but

not chemically, are called mixtures.

Elements Compounds


58/60

Elements, Compounds,

Mixtures

Sodium is an element.

Chlorine is an

element. When sodium and

chlorine bond they

make the compound

sodium chloride,commonly known as

table salt.

Compounds have different properties

than the elements that make them up.

Table salt has different properties than

sodium, an explosive metal, and chlorine,

a poisonous gas.

Elements Compounds


59/60

Elements, Compounds,

Mixtures

Hydrogen is an element.

Oxygen is an element.

When hydrogen and

oxygen bond they make

the compound water.

When salt and water are

combined, a mixture is

created. Compounds inmixtures retain their

individual properties.

The ocean is amixture.

Elements compounds and


60/60

Elements, compounds, and

mixtures

Mixtures can be separated by physical

means.

Compounds can only be separated bychemical means.

Elements are pure substances. When the

subatomic particles of an element are

separated from its atom, it no longer retainsthe properties of that element.

Periodic Table chemistry form 4

Documents

Transcript of Periodic Table chemistry form 4