Modeling Matter

Consider a thought experiment in which you tear a piece of paper in half. Then tear it in half again and then again. How many times could you continue this? Either you divide this piece of paper in half forever or you reach a point where it could no longer be divided in half and still be considered paper.

During electrolysis, water (H₂O) is separated into oxygen and hydrogen, two pure substances. The two gases are collected in separate tubes.

• In 1803 John Dalton separated water into two components

• He realized they always separated into the same ratio

• Twice as much Hydrogen (H₂) than Oxygen (O)

One hypothesis was that large pieces of matter were made up of many tiny particles.

• In the late 1820s, Robert Brown noticed that pollen moved when placed in water (seen here -->)

• One idea was that there were tiny particles crashing into the pollen

• Powerful microscopes have been able to create images of individual particles of matter