Elements and Compounds Lesson

Elements, Compounds and Mixtures

Elements 

• Made up of ONE type of Atom 

• Cannot be broken down chemically into simpler substances 

• Organized on the Periodic Table of the Elements 
  

• Represented by a Chemical symbol 

• Properties can be used to identify different elements 

  
  
  

Chemical Symbol 

• represents the name of an element and is written as a capital letter or a capital letter followed by a lowercase letter

• Examples: H: hydrogen He: helium N: nitrogen O: oxygen C: carbon P: phosphorus S: sulfur Cl: chlorine Na: sodium Si: silicon

Compound 

• A pure substance made by chemically combining two or more elements

• Represented by a chemical formula

• The proportion of each element in a compound is constant (if the subscript is changed, the substance is changed)

Chemical Formula 

•  a representation of a substance (compound) in which the elements are represented by their symbols and subscripts represent the number of atoms of each element

• Possible examples may include: CO2: carbon dioxide CO: carbon monoxide H2O: water NaCl: sodium chloride C6H12O6: glucose CaCO3: calcium carbonate SiO2: silicon dioxide

Multiple Choice

What is a pure substance that cannot be broken down chemically into simpler substances?

• mixture

• element

• compound

• formula

Multiple Choice

An Element is made up of how many types of atoms?

• 12

• 36

• 58

• 1

Multiple Choice

Choose the option that cannot be a chemical symbol.

• a

• H

• O

• Cl

Multiple Choice

What is the result of a CHEMICAL change?

• mixture

• element

• compound

• pure substance

Multiple Choice

What is the building block of all matter?

• legos

• symbols

• letters

• elements

Multiple Choice

Ice melting into water is a ....

• chemical change

• physical change

Multiple Choice

Which is NOT a compound?

• CO₂

• H₂O

• S

• SiO₂