chapter 02

chapter 02 - Atoms, Molecules, and Ions Ancient Greeks and...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 02: Atoms, Molecules, and Ions Atoms, Molecules, and Ions Ancient Greeks and the Elements The ancient Greeks believed that all matter was composed of four elements. These elements were air, water, earth and fire. Each of these elements were related by four principles. These principles were: hot, moist, cold and dry.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 02: Atoms, Molecules, and Ions Ancient Greeks and the Atom Leucippus and Democritus postulated that matter was made up of tiny particles that could not be subdivided further Called them atomos (not divisible) Each type of atom was characterized by a different shape and size. For example atoms of water were smooth round balls. Atoms of fire were jagged and prickly. Aristotle Thought everything was continuous. Matter could be continually subdivided. Atoms didn’t exist they could be subdivided as well. Aristotle asked to be shown atoms Ancient Greeks could not test either model. The scientific method had not yet been developed Since there was no experimental way of proving who was correct, the best debater was the person assumed correct, i.e., Aristotle
Background image of page 2
Chapter 02: Atoms, Molecules, and Ions Scientific Revolution in the late 16 th century, the scientific approach to understanding nature became established for the next 150+ years, observations about nature were made that could not easily be explained by the infinitely divisible matter concept Lavoisier Father of modern chemistry Accurately weighed starting materials and products of reactions He summarized his findings in a Scientific Law. The Law of Conservation of Mass
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 02: Atoms, Molecules, and Ions Antoine Lavoisier (1743-1794) established chemistry as a quantitative science, including the discovery of oxygen in 1788. Law of conservation of mass: Matter is neither destroyed or created during a chemical change Scientist to the end, it is related that as Lavoisier was being led to the guillotine during the French Revolution he told a friend to observe his decapitated head closely as he would attempt to blink his eyes as a last experiment. Reportedly he blinked 11 times. Reaction of Sodium with Chlorine to Make Sodium Chloride the mass of sodium and chlorine used is determined by the number of atoms that combine since only whole atoms combine and atoms are not changed or destroyed in the process, the mass of sodium chloride made must equal the total mass of sodium and chlorine atoms that combine together 7.7 g Na + 11.9 g Cl 2 19.6 g NaCl
Background image of page 4
Chapter 02: Atoms, Molecules, and Ions Historical Perspective (2000 years later) Robert Boyle (1627–1691): Provided evidence for the atoms and defined the nature of an element. Joseph Priestley (1733–1804): Isolated oxygen gas from decomposition of mercury(II) oxide.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/17/2011 for the course CHM 1045 taught by Professor Jeffreyjoens during the Spring '08 term at FIU.

Page1 / 32

chapter 02 - Atoms, Molecules, and Ions Ancient Greeks and...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online