1. Atomic Structures

What is the charge of a proton?

• None of the above

• Neutral

• Negative

• Positive

What is the mass of a neutron?

• 2 amu

• 1 electron mass

• 0 amu

• 1 amu

Where are the protons and neutrons located in an atom?

• None of the above

• Orbitals

• Electron cloud

• Nucleus

What does the atomic number represent?

• Number of protons

• Number of neutrons

• Number of electrons

• Atomic weight

What is the sum of an element's protons and neutrons called?

• Atomic mass

• Isotope number

• Atomic weight

• Mass number

What is the weighted average of the naturally occurring isotopes of an element called?

• Atomic mass

• Atomic weight

• Mass number

• Isotope number

Who first postulated the existence of a dense, positively charged nucleus in an atom?

• Rutherford

• Heisenberg

• Planck

• Bohr

What is the energy difference between energy levels in an atom called?

• Quantum

• Photon

• Electron volt

• Momentum

What does the Heisenberg uncertainty principle state?

• The energy of an electron increases the farther it is from the nucleus

• Electrons do not travel in defined orbits

• Electrons can exist only at certain energy levels

• It is impossible to know both an electron's position and its momentum exactly at the same time

How many quantum numbers completely describe any electron in an atom?

• 3

• 6

• 5

• 4