Elements 
Substance that contains only one kind of atom
Compounds 
-Are substances made of atoms of two or more elements 
that are chemically combined. 
-The chemical formula of a compound shows the elements 
that are in it 
-Example: 
SiO₂ (sand): It is formed of 1 Silicon atom 
2 oxygen atoms
-Compounds don’t have the same properties of the 
elements forming them 
Example: 
The ordinary table salt is a compound called NaCl 
It is formed of : 
1 atom of Sodium and 1 atom of chlorine 
Where “Sodium” is a metal
• And “Chlorine” is a gas 
But when they combine together they give a product of 
different properties which is the table salt
How compounds are formed ? 
-Compounds hold together because atoms bond or 
attach to one another
How atoms can attach or bond with 
each other? 
They either 
Share 
electrons 
Gain 
Or 
lose 
electrons

Elements and compounds

  • 1.
    Elements Substance thatcontains only one kind of atom
  • 2.
    Compounds -Are substancesmade of atoms of two or more elements that are chemically combined. -The chemical formula of a compound shows the elements that are in it -Example: SiO₂ (sand): It is formed of 1 Silicon atom 2 oxygen atoms
  • 3.
    -Compounds don’t havethe same properties of the elements forming them Example: The ordinary table salt is a compound called NaCl It is formed of : 1 atom of Sodium and 1 atom of chlorine Where “Sodium” is a metal
  • 4.
    • And “Chlorine”is a gas But when they combine together they give a product of different properties which is the table salt
  • 5.
    How compounds areformed ? -Compounds hold together because atoms bond or attach to one another
  • 6.
    How atoms canattach or bond with each other? They either Share electrons Gain Or lose electrons