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Sugar- what is it made of?. Carbon- is usually found in pencils or diamond jewelry Hydrogen- is an extremely flammable gas, used in space shuttles Oxygen- is in air. When combined together it makes sugar C 6 H 12 O 6. Different elements combine with each other to form different compounds.
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Carbon- is usually found in pencils or diamond jewelry Hydrogen- is an extremely flammable gas, used in space shuttles Oxygen- is in air
Different elements combine with each other to form different compounds. 5.2 Free atoms are rare in nature. They usually are arranged in proportions. Law of Constant Composition All samples of a given compound have the same proportions of their elements.
Lets look at water If we decompose water we would find 16.0 g of oxygen to every 2.0 g of hydrogen. Mass ratio= 16.0gH/ 2.0g O= 8.0 This is true of any sample of water
Consider ammonia it contains 14.0 g of nitrogen to every 3.0 g of hydrogen. What is the mass ratio? The mass ratio is always calculated by dividing the larger mass by the smaller one.
5.3 Chemical Formulas We represent compounds with a chemical formula H20
CO= carbon monoxide this is an air pollutant CO2= what we breath out
Chemical formulas usually list the most metallic elements first. NaCl not ClNa What do I mean by most metallic? There are few exceptions like hydroxide ion.
Write a chemical formula for the following. The compound containing 2 aluminum atoms to every 3 oxygen atoms. The compound containing 3 oxygen atoms to every 1 sulfur atom The compound containing 3 chlorine atoms to every 1 carbon atom
Some chemical formulas contain several identical groups of atoms. These groups are set in parenthesis and are given a subscript to tell how many Mg (NO3)2
Mg (NO3)2 How to determine the total number of each type of atom. Multiply the subscript outside the parenthesis by the subscript for each atom inside the parenthesis.
5.4 Molecular View of Elements and Compounds Atomic Elements- are those that exist in nature with single atoms as their basic units. Helium Copper Mercury
Molecular Elements- do not normally exist in nature as single atoms instead they exist as diatomic molecules this mean two. H2 O2 Cl2 Molecular Compounds- are compounds formed between two or more nonmetals. H2O CO2 C3H6O
Ionic Compounds- compounds formed between metal and on or more nonmetal Metal tend to lose electrons Nonmetals tend to gain electrons
Classify each of the following substances as an atomic element, molecular element, molecular compound, or ionic compound. CoCl2 Nitrogen SO2 KNO3
Write a chemical formula for the compound containing 2 nitrogen atoms to every 1 oxygen atom.
Classify each of the following as atomic element, molecular element, molecular compound, or ionic compound. Chlorine NO Au Na2O CrCl3