Atomic Theorists

Who was one of the first Atomic Theorists who defined the smallest piece of matter as "atomos"

• Dalton

• Thomson

• Democritus

• Rutherford

Answer explanation

In 430 BC, Democritus said matter is formed of small pieces that could not be cut into smaller parts called "atomos" meaning uncuttable.

True or False: Atoms of one element are all the same.

• True

• False

True or False: Atoms of different elements are different.

• True

• False

John Dalton said Compounds were formed by chemically combining atoms. Are compounds considered Pure Substances or Mixtures?

• Pure Substances

• Mixtures

Answer explanation

Mixtures are substances that are only physically combined. Since Compounds are chemically combined atoms, it would take a chemical reaction to separate them, therefore they are considered Pure Substances.

Which Atomic Theorists used a Cathode and an Anode Ray to discover the negatively charged particles known as electrons?

• Democritus

• Dalton

• Thomson

• Rutherford

Thomson created an atomic model that looks similar to a Chocolate Chip Cookie. What do the chocolate chips represent?

• Protons

• Neutrons

• Electrons

• Nucleus

Answer explanation

In 1897, JJ Thomson did an experiment involving a cathode and anode ray. through the experiment he discovered that atoms contain (-) charged particle, called electrons.

Which atomic theorist did the Gold Foil Experiment to eventually discover the nucleus?

• Democritus

• Thomson

• Bohr

• Rutherford

Rutherford used a Gold Foil Experiment and discovered that atoms are mostly empty space. What did he name the center of the atom?

• Protons

• Neutrons

• Electrons

• Nucleus

Where can you find Protons (+)?

• Inside the nucleus

• In the Electron Cloud

Where can you find the neutrons?

• Inside the nucleus

• In the Electron Cloud