RSM
8th Grade Science
Feb 6, 2013
Go to work station 1 or 2 and get the following items
 One small dry-erase board
 One dry-erase marker
 A paper towel
 Wait for further instructions
To do:
A) Celebrate birthdays
B) Pick new team captains
Notes
SPI 0807.9.3
Elements and Compounds

What Is An Element?
 a substance that CANNOT be broken down into a simpler
substance by CHEMICAL means.
 In other words…you CANNOT change one element into a different
element with a chemical reaction
 Each individual element is a unique particle called an atom
 So in other words… elements are the different types of atoms
Example:
Lithium is an
element.
Here is one
lithium atom
3
Li
Lithium
6.9
Notes
SPI 0807.9.3
Elements and Compounds

More About Elements:
 Elements’ chemical symbols always start with one
capital letter
 Can be followed by one or more lower case letters
Examples:
H = the element hydrogen
 represents one hydrogen atom
Na = the element sodium
 represents one sodium atom
Uub=the element ununbium
 represents one ununbium atom
Notes
SPI 0807.9.3
Elements and Compounds

What Is a Compound?
 …is a substance made up of atoms of two or more different
ELEMENTS that are CHEMICALLY combined via a
chemical reaction.
 EXAMPLES: Notice the elements that were
chemically bonded together to form the following compounds:
NaCl = (Table Salt)
CO2 = (Carbon dioxide)
SODIUM AND CHLORINE
CARBON AND OXYGEN
C6H12O6 = (Glucose) CARBON, HYDROGEN, & OXYGEN
Notes
SPI 0807.9.3
Elements and Compounds

More About Compounds:
 Formulas for compounds will always contain more than
one capital letter.
 This is how you can tell the difference between an element
and a compound… count the number of capital letters!
Examples:
…is a compound for it has more than 1 capital letter
H2O
 This is the compound called water
C12H22O11
…is a compound for it has more than 1 capital letter
 This the compound called table sugar
CH3COOH
…is a compound for it has more than 1 capital letter
 This is the compound called vinegar
Review Activity

Is this an element or a compound?
Write a capital E if you think it is an element
Write a capital C if you think it is a compound
Cs
Element
(Cesium)
Why?...is a pure substance, consists of only one type of atom
How to tell?...It only has one capital letter!
Review Activity

Is this an element or a compound?
Write a capital E if you think it is an element
Write a capital C if you think it is a compound
NaCl
Compound
(Sodium Chloride)
Why?... has two atoms chemically bonded together
How to tell?...It has more than one capital letter!
Review Activity

Is this an element or a compound?
Write a capital E if you think it is an element
Write a capital C if you think it is a compound
Fe
Element
(Iron)
Why?...is a pure substance, consists of only one type of atom
How to tell?...It only has one capital letter!
Review Activity

Is this an element or a compound?
Write a capital E if you think it is an element
Write a capital C if you think it is a compound
MgCl2
Compound
(Magnesium Chloride)
Why?... has two atoms chemically bonded together
How to tell?...It has more than one capital letter!