Science 9 Second Quarter Exam

What does the Quantum Mechanical Model of the atom suggest?

• Electrons travel in fixed orbits

• Electrons are in fixed positions

• Electrons are in probability clouds

• Electrons are stationary

What is the main limitation of Bohr's Model?

• It doesn't explain the behavior of protons

• It doesn't explain the behavior of neutrons

• It doesn't explain the behavior of electrons in atoms with more than one electron

• It doesn't show the electron clouds

In the Quantum Mechanical Model, electrons are located in:

• Fixed orbits around the nucleus

• Random places in space

• Orbitals that form probability clouds

• A single orbital only

What shape does an 's' orbital have?

• Spherical

• Dumbbell-shaped

• Cloverleaf

• Circular

Which orbital shape is represented by the letter 'p'?

• Spherical

• Dumbbell-shaped

• Circular

• Triangular

How many electrons can an 's' orbital hold?

• 1

• 2

• 6

• 8

In the Quantum Mechanical Model, what determines the energy of an electron?

• Its mass

• Its position in the atom

• The color of light it emits

• The number of protons in the atom

Which of these is the correct electron configuration for carbon (C), which has 6 electrons?

• 1s² 2s² 2p²

• 1s² 2s²

• 1s² 2s¹ 2p²

• 1s² 2p⁶

Which rule says that electrons fill orbitals starting with the lowest energy?

• Pauli Exclusion Principle

• Hund's Rule

• Aufbau Principle

• Dalton's Law

How many valence electrons does nitrogen (N) have?

• 3

• 5

• 7

• 8