Chemistry_ Test 1

What are the names of the particles in the nucleus?

• protons and neutrons
• protons and electrons
• photons and neutrons
• nucleons and protons

Who first proposed that everything in the world was made up of tiny particles?

• Aristotle
• Democritus
• Plato
• Socrates

Democritus called the tiniest particles of matter "atomos", which is Greek for _____

• empty space
• invisible
• very small
• indivisible

Dalton showed that common substances always broke down into _____

• the same elements in the same proportions
• elements in equal quantities
• hydrogen and oxygen
• earth, wind, water and fire

The electron was discovered in 1897.  Who discovered it?

• Ernest Rutherford
• John Dalton
• J. J. Thomson
• Niels Bohr

Whose model showed atoms as uniformly packed spheres of positive matter filled with negatively charged electrons?

• J. J. Thomson
• John Dalton
• Ernest Rutherford
• Niels Bohr

J. J. Thomson won a Nobel Prize in 1906.  Which particle did he discover?

• the electron
• the proton
• the neutron
• the photon

Whose experiment involved shooting small, positively charged alpha particles at a sheet of gold foil?

• J.J. Thompson
• Max Planck
• Ernest Rutherford
• Niels Bohr

Who concluded that atoms consisted largely of empty space with most of the mass concentrated in the center?

• J. J. Thomson
• Max Planck
• Ernest Rutherford
• Niels Bohr

Who stipulated that electrons orbit the nucleus at fixed energies and distances?

• Albert Einstein
• Max Planck
• Ernest Rutherford
• Niels Bohr