Alchemy
Alchemists lived back during medieval times. Their ideas were often intertwined with scientific investigations. Alchemists were responsible for the science of chemistry. Alchemists had two objectives: to discover a potion that would bring long life to those who drank it, and to transform common materials into gold.
Alchemists searched for years to find a chemical reaction that would transform base metals into gold. The alchemists believed that gold was a pure substance while lead and other substances were impure. This purity of gold was revered.
The alchemists never achieved their goals, but gold continues to be recognized as a precious metal. Refined gold is relatively rare. However, the alchemists were responsible for the discovery of three important acids: hydrochloric acid, nitric acid and sulfuric acid.
Matter
Most samples of matter around you are mixtures. A mixture contains two or more different materials. Rocks, air, and soil are several such mixtures. Other materials, such as table salt and sugar, are substances. They contain only one kind of material. If the the same substance remains after a change has taken place, then the substance has undergone a physical change. If a new substance is formed, a chemical change has occured. A description of the behavior of a substance undergoing a chemical change is called a chemical property. A description that does not involve such a change is called a physical property.
1. What is the symbol for silver on the periodic table? Is silver an element or a compound?
2. Write the chemical symbol for each of the elements.
a. iron
b. lead
c. copper
d. gold
3. What is the difference between an element and a compound?
4. .A Greek scientist named Archimedes was once posed a problem involving a kings crown. It was suspected that the crown was not pure gold, but a mixture of gold and so-called base metals, such as tin and copper. by carrying out a mass determination and observing how much water was displaced by the crown, and then doing the same for an object of pure gold, archimedes was able, without damaging it, to demonstrate that the crown was not pure gold. This was a density experiment.
a. What is the formula for density?
b. What metric unit is density measured in?.
5. Identify as either an element or compound.
a. carbon f. water
b. aluminum foil g. nitrogen
c. tin h. silicon dioxide
d. carbon dioxide i. helium
e. arsenic j. sodium chloride (salt)
6. When fossil fuels are burned, carbon dioxide and water are produced. What elements must be contained in the fossil fuels? (Assume that the oxygen comes from the air.)
7. Name an element named for a famous scientists.
8. Name an element named after a country.
9. Name an element named after a state.
10. Name an element named after a university.