1.3. The Birth of Chemistry

Learning check

Once you have watched the video, check your learning with this quiz.

When was chemistry born?

Was chemistry born when the first hydrogen molecules started to form in the early universe?

Or was chemistry born when the first humans started to take advantage of chemical reactions (like making a fire) for their survival?

Was chemistry born when metallurgy started to develop?

The bronze age (3200 – 500 BC):

• Bronze = alloy of copper and tin.
• Lower melting point than copper, yet harder.
• Suitable for e.g. weapons – or giant lurs!

A bronze age lur from Brudevælte Mose, Denmark.

A lump of bog iron.

The iron age (500 BC – 800 AD)

• Different times in different parts of the world!
  • Iron age reached the Nordic countries last.
• Bog iron burned with charcoal.
  • Iron with different carbon content obtained ⇒ different qualities.

The ancient philosophers

Was chemistry born when the first philosophers pondered upon what materia was?

Thales of Miletus (625 – 545 BC)

• “Father of philosophy”
• “Water is the permanent entity.”
  
  • It can change form …
• No experiments!

Empedocles (490 – 434 BC)

• Showed that air is not empty space!
  
  1. Put your finger on top of a straw.
  2. Place the straw in a glass of soda.
  3. The soda doesn't enter the straw until you remove your finger ⇒ air is some kind of matter!
• “All matter is made up of water, air, earth, and fire.”

Thales of Miletus (625 – 545 BC).

Empedocles (490 – 434 BC).

With a glass of soda and a straw, you can show that air is not empty space.

Democritus (460 – 370 BC)

• Proposes the first “atomic theory”.
• “Atomos” in Greek means “indivisible”.

Democritus (460 – 370 BC).

Plato and Aristotle in "The School of Athens" (Raffaello).

Plato (428 – 348 AD) and his student Aristotle (384 – 322 AD)

• Favor the idea of four (or five) elements.
• The idea of the four elements persists for 2000 years …

The age of alchemy

Was chemistry born when alchemists first tried to transmute metals?

Middle ages

• Europe’s monks give science “artificial ventilation”.
• Science instead flourishes in the Arabic world.
• Abu Mūsā Jābir ibn Hayyān (“Geber”).

Geber depicted in a manuscript from 1166.

Some of the chemical equipment used by Geber.

Hennig Brand: The last alchemist

• In search of “the philosopher’s stone”.
• Discovers phosphorus 1669.

Hennig Brand discovers phosphorus.

Robert Boyle (1627 – 1691).

The fathers of modern chemistry

Robert Boyle: The first chemist

• “The Sceptical Chymist” (1661).
• Gets rid of “al-” in “alchemy”, and also the magical/mystical part.
• Chemistry must be based on experiments!

Boyle's experiments

• Distinguishes mixtures from compounds.
• Experiments with gases: Sound requires a medium.
• Substances consist of particles with different sizes.

Boyle examined the properties of air using this air pump.

The discovery of oxygen

• Joseph Priestley publishes his findings on "flammable air" 1175.
• Antoine Lavoisier realizes the role of oxygen in combustions, gives oxygen its name.
• (Lavoisier also discovers hydrogen, the conservation of mass, constructs the metric system, writes list of elements …)

Joseph Priestley (1733 – 1804).

Antoine Lavoisier (1743 – 1794) and his wife Marie-Anne.

Jöns Jacob Berzelius develops the chemical language.

• Gives the chemical elements their symbols: H, C, N, O, Fe etc. (1813).
• Introduces chemical formulas.
• Coins the terms catalysis, polymer, protein …
• Compiles a list of atomic weights of the known elements.

Jöns Jacob Berzelius (1779 – 1848).