CH 3 Quiz 3A

What is J. J. Thomson's atomic model called?

• A. the nuclear model

• B. the plum pudding model

• C. the quantum-mechanical model

• D. the Saturnian model

Who proposed the planetary model of the atom?

• A. Niels Bohr

• B. Ernest Rutherford

• C. Albert Einstein

• D. James Chadwick

Which model of the atom incorporates quantum mechanics?

• A. the plum pudding model

• B. the quantum-mechanical model

• C. the Rutherford model

• D. the Dalton model

Which of the following observations did not lead Rutherford to believe that most

of the atom's mass and positive charges were densely packed into a very small

space?

• Some alpha particles bounced off the foil at sharp angles.

• Some alpha particles emitted photons as they fell back into their original energy levels.

• Some alpha particles were deflected at varying angles as they passed through the gold

  foil.

• Most alpha particles passed through the gold foil undeflected.

The Bohr model suggests that electrons move

• in a flat ring around a massive, positively charged center.

• only in distinct, spherical orbits at fixed distances from the nucleus.

• randomly about the nucleus.

• rapidly throughout a uniform, positively charged matrix.

Aristotle first called particles atomos, from which we get our word atom.

• Aristotle discovered particles called atomos.
• Aristotle referred to particles as molecules.
• False. Aristotle called particles atomos.

• Aristotle named particles atoms.

John Dalton proposed that atoms are hard spheres of different sizes and masses.

• False. He proposed that atoms can be divided into smaller particles.

• False. He proposed that atoms are made of liquid substances.

• True. He proposed that atoms are hard spheres of different sizes and masses.

• False. He proposed that atoms are only found in gases.

Scientists currently hold to the quantum-mechanical model because it is able to

precisely pinpoint the locations of an atom's electrons.

• accurately measure the mass of an atom's electrons.
• determine the charge of an atom's nucleus.
• precisely describe the behavior of an atom's electrons.
• predict the color of light emitted by an atom.

If current models have shown the Bohr model of the atom to be inaccurate, why is the Bohr model

of the atom still in widespread use today?

Match the scientist that is usually associated with each of the following:

•  

  J. J. Thomson
  

• discovery of the nucleus

• Niels Bohr

• electrons found in distinct energy levels

• John Dalton

• first modern atomic model

• Ernest Rutherford

• 1. discovery of electrons