Elements, Compounds, and Mixtures

What are the basic differences?

• Element• Any substance that contains only one kind of

atom• Cannot be broken down

• Compound• Consists of atoms of two or more different

elements• Can be broken down

•Mixture• Consists of two or more different

elements/compounds• Can be separated

What is an element?

•Pure Substance•Made up of one kind of atom (smallest

unit)• Homogeneous in structure• Cannot be broken down or separated

• Identified by a chemical symbol (ex. C)•Classified as a metal, nonmetal, or

metalloid• Examples: Hydrogen, Helium,

Oxygen, Carbon, Sodium, Etc.

Types of Elements

What is a compound?

• Is a pure substance• Made up of 2 or more types of elements• Is homogeneous in structure• Cant be broken down or separated by

Physical means• Smallest unit is a molecule• Identified by a chemical formula (H2O)• Created through a chemical change• Held together by a chemical bond• Examples: Sugar, Rust, Water, Carbon

Dioxide

What is a mixture?

• Is a not a pure substance• Made up of 2 or more types of elements• Can be broken down or separated by physical

means• Smallest unit is a molecule• Identified by the ingredients in contains• Classified as homogeneous or heterogeneous• Physically held together with no chemical

bonds• Examples: Sugar water, blood, granite, cereal

with milk, granola bar

Types of Mixtures• Homogeneous• Uniformly mixed on an

atomic/molecular level• Parts do not appear separate• Difficult to take apart• Examples: • Air (includes N2, O2, H2O, CO2),

• Blood (includes red blood cells, white blood cells, plasma, and platelets)

• Heterogeneous• Not uniformly mixed on an

atomic/molecular level• Parts appear separate• Easy to take apart• Examples: Salt and pepper,

chocolate chip cookies

Practice• Classify the following as an element, compound, or mixture

(heterogeneous or homogeneous)• Carbon = • Hydrogen = • Oxygen =• Sugar (C12H22O11)=• Sugar Water that’s completely mixed =• Sugar Water with sugar at the bottom =

Practice• Classify the following as an element, compound, or mixture

(heterogeneous or homogeneous)• Carbon = Element• Hydrogen = Element• Oxygen = Element• Sugar (C12H22O11)= Compound• Sugar Water that’s completely mixed = Homogeneous Mixture• Sugar Water with sugar at the bottom = Heterogeneous Mixture