Chem Ch 4.2

All of the following describe the Heisenberg uncertainly principle except Selected Answer: Answers: a. it helps to locate an electron in an atom. b. it helped lay the foundation for the modern quantum theory. c. it states that it is impossible to determine simultaneously both the position and velocity of an electron or any other particle. d. it is one of the fundamental principles of our present understanding of light and matter.

a. it helps to locate an electron in an atom.

The angular momentum quantum number indicates the Selected Answer: Answers: a. shape of an orbital. b. main energy level of an orbital. c. orientation of an orbital around the nucleus. d. direction of the spin of the electron in its orbital.

a. shape of an orbital.

The French scientist Louis de Broglie theorized that Selected Answer: Answers: a. Bohr's model of the hydrogen atom was completely correct. b. electrons could have a dual wave-particle nature. c. light waves did not have a dual wave-particle nature. d. the natures of light and quantized electron orbits were not similar.

b. electrons could have a dual wave-particle nature.

The spin quantum number of an electron can be thought of as describing Selected Answer: Answers: a. whether the electron's charge is positive or negative. b. the direction of electron spin. c. the electron's exact location in orbit. d. the number of revolutions the electron makes about the nucleus per second.

b. the direction of electron spin.

According to the quantum theory of an atom, in an orbital Selected Answer: Answers: a. electrons cannot be found. b. an electron has no energy. c. an electron's position cannot be known precisely. d. electrons travel around the nucleus on paths of specific radii.

c. an electron's position cannot be known precisely.

All of the following describe the Schrödinger wave equation except Selected Answer: Answers: a. it is an equation that treats electrons in atoms as waves. b. it helped lay the foundation for the modern quantum theory. c. it is similar to Bohr's theory. d. only waves of specific energies and frequencies provide solutions to the equation.

c. it is similar to Bohr's theory.

The quantum number that indicates the position of an orbital about the three axes in space is the Selected Answer: Answers: a. principal quantum number. b. angular momentum quantum number. c. magnetic quantum number. d. spin quantum number.

c. magnetic quantum number.

A three-dimensional region around a nucleus where an electron may be found is called a(n) Selected Answer: Answers: a. orbit. b. electron path. c. orbital. d. spectral line.

c. orbital.

How many electrons can occupy the s orbitals at each energy level? Selected Answer: Answers: a. no more than eight b. one c. two, if they have opposite spins d. two, if they have the same spin

c. two, if they have opposite spins

Both the Heisenberg uncertainty principle and the Schrödinger wave equation Selected Answer: Answers: a. led to locating an electron in an atom. b. are based on Bohr's theory. c. treat electrons as particles. d. led to the concept of atomic orbitals.

d. led to the concept of atomic orbitals.