Periodic Table:

Periodic Table:

1834- 1907

Russian Scientist

Dimitri Mendeleev:

Mendeleev was the first to relate the elements in a systematic logical way.

He listed them by order of increasing atomic mass

Peridic Table

Mendeleev:

He also rearranged the columns so that the more similar elements were next to each other.

Periodic Table:

An arrangement of the elements according to similarities in physical and chemical properties.

Henry Mosley

1887- 1915

British physicist

Rearranged the periodic table

Henry MosleyMosley arranged the table according to atomic number

This is how we view the table today

Modern Periodic Table:

Horizontal rows are called periods

There are seven periods

The number of elements ranges from 2 to 32

Periods

The properties of the elements within a period change

The pattern of properties within a period is repetitive

Periodic Law:

When the elements are arranged in order of increasing atomic number, there is a repetition of physical and chemical properties.

Modern Periodic Table:

Vertical columns are called groups

Each group is identified by a number and a letter

Groups(two general categories)

Identified by numbers and letters

Group A- representative elements

They exhibit a wide range of both physical and chemical properties

Representative elements:

Divided into three groups:1. Metals2. Non metals3. Metalloids

Types of metals: *Types of group A metals:

1. Alkali metals (group 1A)Li, Na, K, Rd, Cs, Fr

2. Alkaline earth metals (group 2A)

Be, Mg, Ca, Sr, Ba, Ra

Other Metals:

A variety of metals with varying chemical and physical properties.

Non- Metals: Elements such as Oxygen and Nitrogen are gases at room temperature

Some non- metals such as sulfur are solids at room temperature and are very brittle

One non- metal element, Bromine is liquid at room temperature

Halogens

Group 7A non metals

Include elements such as Fluorine, Chlorine and Iodine and Bromine

Noble GasesElements that make up the last group of the periodic table

Very stable elements that undergo few chemical reactions

Inert gases

Include, helium, neon, argon, krypton, xenon and radon

Groups continued:

Group B Metals:

represent the transition metals and inner transition metals

Metals:

Properties of:1. Have high electrical conductivity2. Have a high luster3. They are ductile: can be drawn into wires4. They are malleable

Non- metals:

Properties of:1. Non- lustrous2. Poor conductors of electricity

Non- metals:

Some are gases; oxygen and chlorine

Some are brittle solids; sulfur

Metalloids:

Elements with properties that are intermediate between metals and nonmetals.

Example; Silicon