Elements, Compounds and Molecules They “Matter”!!!!

What is MATTER? Matter is anything that has mass, occupies space, and is convertible to energy *Matter has two types of properties: Physical and Chemical

Physical Properties of Matter Can be observed with the 5 senses Can be determined without destroying the object Examples: color, shape, mass, length, odor , density, solubility, taste, melting point, hardness, boiling point, luster, texture

Chemical Properties of Matter These indicate how a substance reacts with something else. The original substance is fundamentally changed while observing a chemical property Examples: rusting (oxidation), flammability, reactions with other substances such as acids or bases, combustibility,

WORKSHEET!!! CAN I HEAR AN “OH YEAH!” Take a few moments to fill out the “Physical VS Chemical Properties” worksheet!

Elements

Elements are pure substances. What are elements? Elements are pure substances. This is because they cannot be broken down into simpler substances. They cannot be made by combining other substances either.

Examples of Elements

How many elements? There are 117 known elements. 92 of the elements can be found in the Earth’s rocks, soil, air and water. The remainder have been made by nuclear scientists.

Atoms and Elements If you could look at the atoms in a chemical element you would see that they are all the same type. For example: If you had a sample of Hydrogen, you would see that all of the atoms looked exactly the same.

Element Symbols Each element in the periodic table is represented by a symbol of one or two letters. These letters (symbols) come from the English, Latin or Greek name for the element. The first letter is always a CAPITAL and the second letter (if there is one) is always lower case.

Elements and the Periodic Table The elements are organised and presented in the Periodic Table. The Periodic Table displays the following information about an element: Symbol Name Atomic number Atomic weight (not always)

Atomic number Element symbol Element name Atomic weight

Now lets diagram the parts of an element on the periodic table!

Question… How can only 92 naturally occurring chemical elements form millions of different types of materials?

Compounds

What are compounds? Compounds are formed when two or more different elements chemically combine. This process is called a chemical reaction. The new compound formed has different properties from the original elements.

+  Compound: Water Hydrogen Oxygen Water Water forms through the following reaction: +  Hydrogen Oxygen Water Element Element Compound

H2O More about compounds Compounds always have the same ratio of elements. For example: Water always contains two atoms of hydrogen to one atom of oxygen. For this reason, water has the chemical formula: H2O

Compound: Water H2O 2 atoms of Hydrogen 1 atom of Oxygen

How do elements and compounds exist? Some chemical elements, such as gold, mercury, helium and neon are found in nature as single atoms. Others such as hydrogen, oxygen and nitrogen can be found with more than one atom (the same type of atom) joined together.

Molecules When two or more atoms join together (the same or different atoms) a molecule is formed. The atoms are tightly joined. These bonds between atoms in a molecule are called chemical bonds. These chemical bonds cannot be easily broken.

More about molecules Molecules that are elements: Atoms are the same compounds: Atoms are different.