4-4 Review and Reinforcement

as particles and waves

How does the quantum-mechanical model of the atom describe electrons?

electron spin

the clockwise or counterclockwise motion of an electron

a. s orbital

The first principal energy level of the hydrogen atom contains only a(n) a. s orbital b. p orbital c. d orbital d. f orbital

electron density

the density of an electron cloud

b. larger

The 3s orbital differs from the 2s orbital in that it is a. smaller b. larger c. a different shape d. more crowded

c. quantum number for that energy level

The number of sub levels in each principal energy level equals the a. mass of the atom b. electron density of the atom c. quantum number for that energy level d. number of electrons in the atom

Pauli Exclusion Principle

states that each orbital in an atom can hold at most two electrons and that these electrons must have opposite spins

principal energy level

the main energy levels in an atom

c. dumbbells

All p orbitals are shaped like a. spheres b. doughnuts c. dumbbells d. footballs

b. lowest

The electron cloud is least dense where the probability of finding an electron is a. greatest b. lowest c. highly likely d. nonexistent

c. s, p, d, and f

Which sub levels can be found in the fourth principal energy level of an atom? a. s and p b. s, p, and d c. s, p, d, and f d. s, p, d, f, and g

orbital

a region in space where an electron with a particular energy is likely to be found

quantum-mechanical model

explains the properties of atoms by treating the electron as a wave and quantizing its energy

quantum number

number designating a principal energy level in an atom