Physical properties distinguish one object from another, can be observed or measured without changing the substance. Chemical Properties describe how a substance unites with other substances to form a new substance.
What is a chemical change?
What is the difference between elements and compounds?
Molecules: groups of two or more atoms linked together.
Different compounds can be formed from the same elements Examples: Carbon, Hydrogen, and Oxygen Make: Sugar Formaldehyde Aspirin Rubbing Alcohol
Match the term to what it means: Molecular Mass Pure Substances Elements and Compounds can be Mixtures What are used to separate mixtures Pure Substances Sum of the atomic masses of all the atoms Chemical composition is the same throughout Made of several elements that are physically mixed Physical Methods
What are the three types of mixtures?
Solution, colloid, and Substance
Suspension, Sand and Sugar, Elements
Colloid, Compounds, Cookies
Bob, Suspension, Colloid
Solution, Colloid, and Mixed Discrete Particles
Molecules of two substances are completely mixed
Tiny clumps or particles that stay suspended within the mixture
Discrete Particle Mixture:
When particles of one mixture are mixed with the discrete particles of another substance
Types of Mixtures
Naming Simple Compounds: Named by the composition of the compound (last element ends in –ide) Mono- Tri- Hexa- Deca- Tetra- 4 6 1 3 10
Naming Simple Compounds: Named by the composition of the compound (last element ends in –ide) Di- Penta- Nona- Octa- Hepta- 7 9 2 5 8
Compound Naming Hints:
Mono is only used when there are other compounds made of the same elements
Some compounds have common names that are used
Dihydrogen Monoxide= H2O (Water)
Use chemical symbols to quickly write formulas
Formulas: the written representation of the number and types of elements
Three types of molecules:
1. Molecular formula – short hand for writing the number of each atom
2. Structural formula – most informative type of written formula and shows how the molecules are arranged
3. Empirical formulas – shows only the simplest ratio of atoms in a molecule