Elements, Compounds, and Mixtures
Compounds can be identified by...chemical formula
*By the Compound's Chemical Formula - Element plus Element = Compounds H2 + O2 = H20
How to identify a Mixture
*Mixtures are substances that are held together by physical forces NOT chemical bonds. *Mixtures are made up of a combination of elements and/or compounds. *Mixtures can be separated through physical methods: pick out the different particles, filter, distillation, magnet and centrifuge.
Mixtures
A combination of two or more substances that are not chemically combined.
Heterogeneous
A mixture composed of different parts or elements. *Can be viewed separately- Not Uniform *Does not blend with one another *Retains their physical identities *Can contain more than one phase of matter Examples: sandy water, Coke or Pepsi, Orange juice with pulp, Chicken Noodle Soup, a cookie.
Solution
A mixture that forms when one substance dissolves another.
Homogeneous
A mixture that has the same kinds of elements and a uniform composition. *The composition of the substance is uniform throughout the mixture. *Only one phase of matter. *Individual ingredients cannot be viewed separately. Examples: Brewed coffee or tea, soapy water, Blood, Sugar or salt dissolved in water, apple juice, air, and mouthwash.
Element
A pure substance that cannot be separated into simpler substances by physical or chemical means.
Pure Substance
A substance in which there is only one type of atom or particle.
Elements can be identified by...
By the element's Chemical Symbol - Fe, O, Cs, Be, Xe
Elements can be identified by...
By the element's atoms or particles - only one type of atom is present in an element.
A carbohydrate is made of carbon, hydrogen, and oxygen. This is a ...
Compound
Element, Compound, Mixture? Acetic Acid
Compound
Element, Compound, Mixture? Diamond
Compound
Element, Compound, Mixture? NaOH
Compound
What is the difference between a mixture and a compound?
Compounds contain elements bonded together.
Element, Compound, Mixture? Kr
Element
What is the difference between an elemental molecule and a compound molecule?
Elemental molecules have only one element, and compound molecules have more than one.
Why are compounds considered a pure substance?
Elements are chemically bonded together and lose their original properties to make a new substance.
Chemical Bonds
Forms when two or more substances combine.
How many different elements make up one molecule of.... glucose (C6H12O6) Water (H2O) Oxygen (O2)
Glucose =3 (Carbon, Hydrogen, Oxygen) Water = 2 (Hydrogen, Oxygen) Oxygen = 1 (Oxygen)
Examples of Common Mixtures
Granite, Blood, Pizza, Saltwater
Compounds can be identified by...
How they are chemically combined (joined together)
Element, Compound, Mixture? Air
Mixture
Why is a combination of sugar and salt classified as a mixture?
No new chemical bonds are formed between the salt and sugar grains.
Pure Element
Only one type of atom present
Pure Compound
Only one type of compound present
Element can be identified by....
Periodic Table of Elements - if you can find it on the table, its an element.
True or False: Air is a mixture
True
Molecule of an Element
Two or more atoms of the same element
Compounds
Two or more elements chemically combined or bonded. A pure substance containing two or more kinds of atoms
Mixture of two compounds
Two types of compounds present
Mixture of two elements
Two types of uncombined atoms present
What substance can be separated into simpler substances only by chemical means?
Water
How would you classify Water and Oxygen?
Water = compound Oxygen = element
Examples of Compounds
Water, Carbon Dioxide, Sugar, Baking Soda, Salt
Compounds can be identified by....
When Elements bond to form Compounds, the chemical bonding (reaction) can change both the physical and chemical properties of the substance.