Pages 311 - 352

What are the parts of an atom?

Nucleus – The center of the atom. It contains…

Protons – Positively charged particles.

Neutrons – that have no charge.

Outside the nucleus… Electrons – Negatively

charged particles. Every atom of the same

element has the same number of protons.

What is the Periodic Table?

It’s an arrangement of elements showing the repeating pattern of properties.

Created by Mendeleev

He grouped them according to chemical and physical properties.

How do you read the Periodic Table?

For each element it tells the Atomic Number, the Atomic Mass, The Chemical Symbol, and the Chemical Name.

The Atomic Number tells the number of protons (and usually the number of electrons)

Atoms with a different number of electrons than protons are called ions and are electrically charged particles.

What is Atomic Mass?

It is the average mass of all the isotopes of that element.

(Remember, an Isotope is an element that has the same amount of protons but a different amount of neutrons changing it’s mass.)

How is the Periodic Table Useful?

An element’s properties can be predicted from looking at its location in the Periodic Table.

Atomic Numbers are in order from left to right, and similar properties are grouped together in columns.

What is a period?

A row on the Periodic Table.

Properties change in a predictable way as you go from left to right.

Metals are shown on the left and nonmetals on the right with metalloids in the middle.

What is a Group?

The elements in a column form a group.

Each group is known as a family.

The Elements in each group have similar characteristics.

For example – all elements in group 1 (except for hydrogen) are metals that react violently with water.

How are elements grouped together?

The elements are grouped together in three main categories:

Metals Nonmetals Metalloids

What are the properties of metals?

Physical: High luster – shiny and

reflective Malleable – can be

hammered into flat sheet

Ductile – can be pulled out or drawn into a wire

Thermal conductivity – can transfer heat

Electrical conductivity – can transfer electricity

Properties of metals cont…

Chemical:

Reactivity – the ease or speed that elements react or combine with other elements. Most metals react by losing electrons to other atoms.

Corrosion – the gradual deterioration of a metal due to a chemical reaction with the environment.

How are metals classified?

Metals are classified into 6 categories:

Alkali metals Alkaline earth metals Transition metals Metals in mixed

groups Lanthanides Actinides

What are Alkali Metals?

They are VERY REACTIVE!!!!!

The metals in group 1 from lithium (li) to francium (Fr)

They are never found by themselves in nature – always in a compound.

They are shiny and very soft – some can be cut with a plastic knife!

They have low densities and low melting points – ex. Sodium melts at 98 C and is less dense than water!

Alkaline Earth Metals

Reactive – but not as reactive as the alkali metal group.

They are more dense and melt at higher temperatures – ex. Magnesium (Mg) melts at 648.8 C.

Calcium is one of the most common alkaline earth metals – needed for healthy bones.

Transition metals

Most are hard and shiny solids (except for Mercury which is a liquid at room temp.)

Includes iron, copper, nickel, gold and silver.

High melting points and high densities.

Good conductors Very malleable Less reactive than 1-2

Metals in mixed groups

Only some of elements in groups 13 – 16 are metals.

Include Aluminum, Tin, Lead.

Not very reactive – used to coat other metals so they won’t corrode.

Lanthanides and Actinides

Many of these elements are synthetic (not naturally found but artificially made in laboratories).

They are made using particle accelerators.

Transuranium Elements

The synthesized elements found on the table past Uranium. They are made by crashing the nuclei of atoms together at extremely high speeds using particle accelerators.

What are the properties of Nonmetals?

Physical: Dull Brittle Poor conductors of

both heat and electricity.

Nonmetals cont….

Chemical Properties: Atoms of nonmetals

usually gain or share electrons with other atoms. Electrons move from metals to nonmetals. Sometimes nonmetals join together to form compounds such as H2O

Families containing Nonmetals

The Carbon Family The Nitrogen

Family The oxygen Family The Halogen

Family The Noble Gases Hydrogen

The Carbon family

Group 14 Most fuels used to

yield energy contain carbon such as coal, gasoline, crude oil.

Carbon is important to life – proteins, carbs, DNA, fats.

Diamonds are pure carbon.

Nitrogen family

Oxygen family

Group 15 Contains 2

nonmetals – Nitrogen and Phosphorous.

Group 16 Contains 3

nonmetals – Oxygen, Sulfur, and Selenium. O – gas

S & Se - solids

Halogen family

Group 17 Nonmetals include

Florine, Chlorine, Bromine and Iodine.

Halogen means “salt forming”

Although halogen elements are dangerous – they are useful – water treatment, toothpaste.

The Noble Gases

Group 18 Usually

nonreactive. Helium (He), Neon

(Ne), Argon (Ar), Krypton (Kr), Xenon (Xe).

Used in Balloons and Neon lights.

Hydrogen Alone in the upper left corner of the Periodic table.

Properties very different than all others, so it is not grouped with a family.

Hydrogen makes up more than 90% of all atoms in the universe, but only 1% on Earth.

What are Metalloids?

They have some properties of metals and some of nonmetals.

Solids Brittle, hard,

somewhat reactive. Semiconductors

(conduct electricity under certain conditions)

Models 0f atoms….

Notes…..