The Periodic TableBy: Aditi Kamble and Saachi Katariya

Main IdeaScientists have identified more than 100 elements.

Metals

Semimetals

Nonmetals

The elements are organized in a periodic table.

Lesson SummaryDmitri Mendeleyev created the first periodic table

He left blank spaces for elements that he believed would be discovered later

Periodic Table: presents basic information for each element

Elements are classified as nonmetals, semimetals, and metals

Most metals are good conductors of heat and electricity

VocabularyChemical Symbol: An abbreviations of an element name

Metal: A shiny substance that can be bent or stretched, and can conduct electricity

Noble Gas: An element that hardly ever combines with another element to form a compound

Non Metal: An element, usually in a form of gas, that cannot conduct electricity, does not stretch or are bend very much, and can break easily.

Periodic Table: The table that logically arranges all known elements.

Semimetal: an element that is like in some ways and like nonmetal in some ways.

Organizing the Elements

Scientists have identified more than 1oo different kinds of elements

Greek philosopher: Empedocles thought matter is made of 4 different kinds of elements

fire, water, air, and earth

Later, scientists identified more elements that fit in the periodic table

Mendeleyev’s Table

In 1869, Dmitri Mendeleyev developed a way to arrange and classify the elements.

Dmitri Listed the elements in order of increasing mass.

Noticed a pattern repeating itself.

He rearranged the list so that the elements with similar properties would appear in the same column.

He predicted that in the future scientists would discover the elements that would fit in the blank spaces he left.

Mendeleyev's Table Cont.

Today scientists use a table of elements similar to Mendeleyev's

The periodic table is standardized

Mendeleyev could not explain why should the pattern in the periodic table should exist

Mendeleyev's Table

The Periodic TableElements are arranged by increasing atomic number

Each box in the periodic table shows the atomic number, chemical symbol, and the name of the element

Each column in the periodic table is called a group

Each horizontal row is called period

The Periodic Table Cont.

Elements can be classified as nonmetals, semimetals, and metals. Metal: bendable, conduct electricity, and can be stretchedNonmetals have properties that are the opposite of a metalSemimetals have nonmetal and metal characteristicsElements Bromine and Mercury are liquids, The symbols in red are gases and the ones in black are solids

MetalsMetals include such familiar elements such as: iron, gold, nickel, silver, and aluminum.

It also includes rarer metals such as: Technetium and Francium.

One property that metal has is luster.

They are not easily bent.

They also conduct electricity.

Most metallic objects are made from more than 1 metal.

SemimetalsSemimetals: located between metals and nonmetals known as metalloids

Semimetals: have the same properties like nonmetals and metals

One example of a semimetal is silicon and 28% of earth crust is made from silicon

Used to make electric circuits found in computer chips

NonmetalsSolid nonmetals are dull in color.

Do not conduct electricity

They are brittle

Many nonmetals are gases

Noble GasesThe last group of the periodic table is noble Gas

Noble gas will glow if electric current passes through it.

This makes neon

Different gas mixtures make different colors.

Beyond The Book

Rare and Common Elements

99% of Earth is made of elements

8 elements make up Earth’s crustOxygen

Silicon

Potassium

Aluminum

Iron

Sodium

Calcium

Magnesium

Elements combine to form compounds

Carbon Compounds

There are nearly 10 million elements known as carbon compounds

Important group of compounds: hydrocarbons. These are important fuels

Carbon Compounds are the main parts of all living things

Carbon Compounds fall into four main groupsCarbohydrates

Proteins

Lipids

Nucleic Acids

POP QUIZ!!!!!1. What is one element that makes up the

Earth’s crust?A. Iron

B. Banana

C. Minions

D. Donkeys

2. What is one property of a metal?A. Potatoes

B. Milk

C. Luster

D. Mr.Ashraf

POP QUIZ #23. What are the 4 main groups of the carbon compounds?

A. Pegasus, Donkey, Horse, Unicorn

B. Carbohydrates, Proteins, Lipids, Nucleic Acids

C. 1,2,3,4

D. 100000,200000,300000,4000000

Thank You For Watching

Any Questions???