The Periodic Table - Plainfield South High...

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Atoms and the Periodic Table

Parts of the Atom

• Proton

–Found in the nucleus

–Number of protons defines the element

–Charge +1, mass 1

Parts of the Atom

• Neutron

–Found in the nucleus

–Stabilizes the nucleus

–Charge 0, mass 1

Parts of the Atom

• Electron

–Found outside the nucleus in the electron cloud

– Does all the work in chemical reactions

–Charge -1, mass 0

ISOTOPES

• Atoms of a given element are not all identical

–They can have different masses

–Chlorine has atoms with masses of

35 amu and 37 amu

These are called isotopes

ISOTOPES

• Atoms of a given element with different masses are called isotopes

– They can have different masses because they have different numbers of neutrons

– Chlorine has atoms with a masses of

35 amu and 37 amu

Both have 17 protons, but the isotope with a mass of 35 has 18 neutrons and the one with a mass of 37 has 20 neutrons

ISOTOPES

• Name an isotope in one of these ways:

Cl1737

37 is the Mass number (# of protons + # of neutrons)

17 is the number of protons

ISOTOPES

• Name an isotope in one of these ways:

Chlorine-37

37 is the mass number of the isotope

ISOTOPES

• Some Isotopes are not stable

–When they decompose, some mass changes to energy. This energy is radiation

• Marie and Pierre Curie researched radioactive isotopes in 1903

How do we know how many?

• Number of protons is the same as the atomic number

• Number of electrons is the same as the number of protons

• Number of neutrons is the atomic mass minus the number of protons

We get these numbers from the Periodic Table

12.011

Atomic

Number

Symbol

Atomic Mass

Practice Time!

12.011

Atomic

Number is

the number

of electrons

Symbol

Atomic Mass

Round atomic

mass to a whole

number and

subtract the

number of protons

to find the

number of

Atomic

number is

the number

of protons

Practice

CCarbon12.011

Atomic number = number of

___________ or ____________

Atomic mass = the number of

_____________ + ____________

# Protons = ___________# Neutrons = ___________# Electrons = ___________

Practice

OOxygen15.9994

___________ or ____________

_____________ + ____________

Practice

___Zinc

___________ or ____________

_____________ + ____________

Practice- an Isotope

Summary

• Fill in the parts of the atom.

Parts of the Atom

The Electron

Cloud-

Mostly empty

Space, Has most

of the volume of

the atom

Location in

the Atom

he Nucleus-

Contains

most of the

mass of tThe

Part of the

Electrons

Protons

Neutrons

Charge

Number

Mass =0

Charge

Mass =1

Charge = 0

Mass =1

Charge = 1

How to get

that number

from the

periodic table

= # of

protons

= atomic

= mass –

# of protons

The Atom

The Electron

Cloud-

Mostly empty

Space, Has most

of the volume of

the atom

Location in

the Atom

The Nucleus-

Contains

most of the

mass of the

Part of the

Atom and

Who Found it

Electrons

Protons

Neutrons

Charge

Number

Mass =0

Charge

Mass =1

Charge = 0

Mass =1

Charge = 1

How to get

that number

from the

periodic table

= # of

protons

= atomic

number

= mass –

# of protons

Periodic Table Important Terms

• Period- a row on the periodic table

Periodic Table Important Terms

• Group (also called a family) A column on the periodic table. All elements in the same group have similar properties.

Parts of the Periodic Table

• Metals, Nonmetals and Metalloids1

Properties of Metals• Good conductors of heat and electricity

• A clean metal surface will be shiny or “lustrous”

• Solids at room temperature

– (Except mercury [Hg])

• Ductile- can be made into wire

• Malleable- can be hammered into shapes without breaking

Properties of Non-metals

• Properties vary a lot

• Most are gases, but the ones that are not have low melting or boiling points

• Poor conductors of heat or electricity (except carbon)

• If solid, they are brittle – they break easily

• Usually not shiny

Properties of Metalloids

• Also called semi-metals and semiconductors

• Under some conditions they act like metals

• Under other conditions they act like non-metals

• Used in computers and other electronics

The Individual Squares

Fe55.85

Location on the Periodic Table

• Groups

– Elements in the same groups have similar properties

Elements that “Don’t Belong”

• Hydrogen

– The smallest, lightest element.

– All the other elements get made from hydrogen in the cores of stars or when stars explode.

– Electron configuration is 1s1

Groups to Know• Alkalai metals (group 1 )

– Li, Na, K, Rb, Cs, Fr

– Metals

– Soft

– Very Reactive

• Always found combined in nature

• Will react with water

– All solids at room temperature,

but have rather low melting points

Group 1(1A)

Groups to Know• Alkalai earth metals (group 2 )

– Be, Mg, Ca, Sr, Ba Ra

– Metals

– Soft, but not as soft as group 1

– Reactive (but not as reactive as group 1)

• Will react with very hot water or steam

– All solids at room temperature

Group 2(2A)

Groups to Know• Halogens (group 17 )

– F, Cl, Br, I, At

– Non-metals

– Change from gas to liquid to

solid as you go down the group

– Very Reactive

• Name means (salt-maker)

Group 17(17A)

Groups to Know• Noble Gases (group 18 (8A))

– He, Ne, Ar, Kr, Xe, Rn

– Non-metals and all Gases

– Very non-reactive

Group 18(18A)

2 13 14 15 16 17

Groups to KnowMain Group Elements

Groups 1,2,13,14,15,16,17,18

Also called “Representative

Elements”

3 4 5 6 7 8 9 10 11 12

Groups to Know

• Transition Metals

– Groups 3,4,5,6,7,8,9, 10,11,12

• On some Tables : All the columns with “B” after the number

Groups to Know

• Transition Metals

• Also includes the Lanthanides and Actinides

– The two rows below the periodic table

– Called “Inner Transition Metals”

Groups to Know• Transition Metals

Properties are those for metals

Usually high melting points

Usually not very reactive

Conductive

The Periodic Table - Plainfield South High...

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