Unit 1Atomic Theory

What is the average atomic mass of magnesium?

• 23.9850 amu
• 24.9858 amu
• 25.9826 amu
• 24.3050 amu

What information does electron configuration notation provide?

• The weight of a file
• The number of electrons in each sublevel
• The number of papers in a folder
• The size of an atom

How is electron configuration notation different from orbital filling diagrams?

• It uses boxes and arrows
• It counts the number of arrows
• It adds up the numbers in the electron configuration
• It eliminates the need for counting

What is the shape of an s orbital?

• Spherical
• Dumbbell
• Complex
• Cylindrical

Which quantum number determines the shape of an orbital?

• Principal quantum number (n)
• Angular momentum quantum number (l)
• Magnetic quantum number (ml)
• Spin quantum number (ms)

Who proposed the first complete atomic theory?

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

What did J. J. Thomson's experiments with cathode rays reveal?

• The presence of electrons
• The existence of protons
• The structure of the nucleus
• The behavior of neutrons

Which model of the atom proposed that electrons orbit the nucleus in fixed paths called 'shells' or 'energy levels'?

• Dalton's model
• Nagaoka's model
• Rutherford's model
• Bohr's model

What did Ernest Rutherford's gold foil experiment suggest about atomic structure?

• Atoms are indivisible
• Atoms consist of a dense nucleus
• Atoms have a positive charge
• Atoms have fixed energy levels

Who discovered the neutron?

• John Dalton
• J. J. Thomson
• Ernest Rutherford
• James Chadwick