Transcript Elements Compounds - Science with Mrs. Schulte

Classifying Matter:
Elements, Compounds, and Mixtures
Classifying Matter
Pure Substances
 A sample of matter in which every piece is exactly the same
down to the molecular level
Elements
 pure substance that cannot be separated into simpler
substance AT ALL!
Compounds
Pure substance composed of two or more elements joined by
chemical bonds.
 Made of elements in a specific ratio
that is always the same
 Has a chemical formula
Types of bonds
 There are two main types of bonds between atoms
Ionic bond:
 Bond between two atoms that transfer electrons
 The bond between a metal and a non-metal
 Creates ions (charged atoms) to be formed
Ionic bond – electron from Na is transferred to Cl, this
causes a charge imbalance in each atom. The Na becomes
(Na+) and the Cl becomes (Cl-), charged particles or ions.
Covalent bond:
 The attraction that forms between
atoms when they share electrons.
 Bond between two non-metals
Compounds
Pure substance composed of two or more elements joined by
chemical bonds.
 Can only be separated by
chemical reaction, not physically
Compounds
 Properties are different than the elements they are made
from
 Example:
Mixtures
 A combination of two or more pure substances that are not
chemically combined.
 Each item keeps its original properties
in the mixture
 They can be separated physically
Chem4kids.com
Homogeneous Mixtures
 Molecules are mixed up in an even distribution
Solutions
 A mixture that appears to be a single substance (smallest size
particles)
 Solute- the substance being dissolved
 Solvent- the substance in which the solute is being dissolved
 Water is considered the universal solvent, it will dissolve
more substances than any other in the world
 Examples: sugar water, lemonade, Kool-Aid, soda, air
Heterogeneous Mixture
 Molecules are not mixed up in an even distribution
Mixtures vs. Compounds
http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/elements_com_mix_6.shtml
Can you identify the following?
You will be shown a series of photos. Tell if each photo
represents an item composed of an element, compound, or
mixture.
Review:
 An element contains just one type of atom.
 A compound contains two or more different atoms joined
together.
 A mixture contains two or more different substances that
are only physically joined together, not chemically.
 A mixture can contain both elements and compounds.
Hints to tell the difference:
Element, Compound, or Mixture?
Rocks
Element, Compound, or Mixture?
Rocks
Element, Compound, or Mixture?
Copper
Element, Compound, or Mixture?
Copper
Element, Compound, or Mixture?
Jelly Beans
Element, Compound, or Mixture?
Jelly Beans
Element, Compound, or Mixture?
Table Sugar
Element, Compound, or Mixture?
Table Sugar
Element, Compound, or Mixture?
Diamond
Element, Compound, or Mixture?
Diamond
Element, Compound, or Mixture?
Tea
Element, Compound, or Mixture?
Tea
Element, Compound, or Mixture?
Salt
Element, Compound, or Mixture?
Salt
Element, Compound, or Mixture?
Neon Gas
Element, Compound, or Mixture?
Neon Gas
Element, Compound, or Mixture?
Salad
Element, Compound, or Mixture?
Salad
Element, Compound, or Mixture?
Pure Water
Element, Compound, or Mixture?
Pure Water
Element, Compound, or Mixture?
Aluminum
Element, Compound, or Mixture?
Aluminum
Element, Compound, or Mixture?
Lemonade
Element, Compound, or Mixture?
Lemonade
Element, Compound, or Mixture?
Silver
Element, Compound, or Mixture?
Silver
Element, Compound, or Mixture?
Sand
Element, Compound, or Mixture?
Sand
Classifying Matter Diagrams
Examples
 Air (CO2 + NO2 + H2O)
 Gold (Au)
 Glucose (C6H12O6)
 Oxygen in water (O2 + H2O)
 Steel (Fe and C)
 Ocean Water (NaCl + H2O)
 Sulfur (S)
 Bronze (Cu + Sn)
 Carbon Dioxide (CO2)
 Chlorine Water (H2O + Cl2)