- Properties you can observe directly
- Water is a colorless, odorless substance that exists as a liquid at room temperature.
- Gold is shiny, exists as a solid at room temperature, and can be pounded into very thin sheets.

Physical Properties

- Properties that can only be observed when
one substance changes into a
different substance

- For example, if you leave an iron nail outside, it will eventually rust.

Chemical Properties

-118 Elements
-90 elements occur naturally
-The periodic table organizes the elements according to how they combine with other elements due to their chemical properties.

-Easiest pattern is increasing atomic number
-Hydrogen is the lightest
-Oganesson is the heaviest

Elements

Periods and Groups

Periods = Rows

Groups = Columns

Organization

A metal is typically shiny, opaque, and a good conductor of heat and electricity as a pure element. Metals are also ductile, which means they can be bent into different shapes without breaking.

Metals are on the left side of the periodic table.

Metals

Nonmetals are poor conductors of heat and electricity. Solid nonmetals are brittle and appear dull.




Nonmetals are on the right side of the periodic table.

Nonmetals

The elements on the border between metals and nonmetals are called metalloids.

Sometimes act like metals, sometimes act like nonmetals.

Metalloids

-Group 1

-Soft and silvery in their pure form

-Highly reactive

Alkali Metals

-Group 17

-Tend to be toxic in their pure form

-Highly reactive

-When combined with alkali metals they form salts

Halogens

-Group 18

These elements do not naturally form chemical bonds with other atoms and are almost always found in their pure state.

Not very reactive!

Noble Gases

-Middle of the periodic table

-Usually good conductors of heat and electricity

Transition Metals

Energy Levels

Energy Levels

Periodicity - the repeating pattern of chemical and physical properties of the elements.

Most elements are solid at room temperature

-11 are gases at room temperature

-2 are liquid at room temperature

Room Temperature States