Unit 1: Elements and compounds

UNIT 1: ELEMENTS AND COMPOUNDS

Lesson 1: What are metals?

METAL

A substance that transfers heat and electricity well and is malleable

NONMETAL

A substance that does not transfer heat and electricity well and is not malleable

MALLEABLE

Easy to shape or to form

ALLOY

A solid solution in which a metal or a nonmetal dissolves in a metal

METALLOID

A substance that has some of the properties of a metal and some of the properties of a nonmetal

METALS AND NONMETALS Metals are a good conductor of

heat and electricity because they heat up quickly, and electricity passes through them quickly.

75% of all elements are metals. Metals, with the exception of

hydrogen, are located on the left side of the periodic table.

Nonmetals are located on the far right side.

If a substance looks like a metal it is called metallic. They often reflect light and are often shiny. Most metals are grey or silver in color.

In addition, metals are malleable, which means they are easily shaped or formed.

PROPERTIES OF METALS Elements that are

in the same column of the periodic table are called a family.

This means that they are related, just like members of a real family.

Also most elements in the same family have the same physical properties.

OTHER PROPERTIES OF METALS Metals that are good

conductors of heat have a high thermal conductivity.

Metals that are good conductors of electricity have a high electrical conductivity.

Materials that do not conduct heat or electricity well are called insulators.

SEEING METAL ATOMS Atoms are small. 20 million

large atoms placed side by side would only measure one centimeter.

These small atoms are visible with an electron microscope.

Another type of microscope called scanning tunneling microscope (STM), uses a probe to examine the surface of a material.

Today, scientists can use STMs to check for flaws in materials and observe molecules.

ALLOYS AND METALLOIDS An alloy is formed

by combining metals or by combining a metal and a nonmetal.

Metalloids , or semimetals, are elements that contain properties of metal and some nonmetals.

ONLINE RESOURCESProperties of Metals (0:49)http://

www.youtube.com/watch?v=cWKzKX565eU

Periodic Table Song (3:36)http://

www.youtube.com/watch?v=5kbe57m-tpY