Chp. 9: Electrons in Atoms in the Periodic Table

Light is a form of ______ _______.

electromagnetic radiation

Light has properties of both _______ and _______.

waves; particles

wavelength is represented by the variable:

λ (lambda)

The wavelength of light, represented by λ, is defined as the distance between:

adjacent wave crests.

What occurs when an electron is excited?

energy absorption; electrons move outwards

What occurs when an electron relaxes?

light emits; electrons move towards the atomic nucleus

The levels of the Bohr model are called:

orbits

Since the amount of energy in a photon is directly related to its ________, the photon has a specific wavelength.

wavelength

The Bohr model was replaced with the ___________ or __________ model.

quantum-mechanical; wave-mechanical

In the quantum-mechanical model, Bohr orbits are replaced with quantum-mechanical:

orbitals.

In the 1s orbital, the number denotes the ____________ while (n) specifies the principal shell of the orbital.

principal quantum number

In the 1s orbital, the number denotes the principal quantum number while (n) specifies the:

principal shell of the orbital.

When an atom is undisturbed, it is said to be at ______ state.

ground

When an electron is in a higher-energy orbital, the atom is said to be in an ______ state.

excited

All the atoms of each element have ___ ground state and ____ excited states.

one; many

The higher the principal quantum number, the _______ energy of the orbital.

higher

The Pauli exclusion principle states that orbitals may hold:

no more than two electrons with opposing spins.

The ___________ states that orbitals may hold no more than two electrons with opposing spins.

Pauli exclusion principle

Hund’s rule states that, when filling orbitals of equal energy, electrons:

fill them singly first, with parallel spins.

_________ states that, when filling orbitals of equal energy, electrons fill them singly first, with parallel spins.

Hund’s rule

Valence electrons are the electrons in the:

outermost principal shell.

_________ electrons are the electrons in the outermost principal shell.

valence

Electrons that are not in the outermost principal shell are called:

core electrons.

If chlorine (Cl) is in the column with group number 7A, how many valence electrons does it have?

7

The chemical properties of elements are largely determined by the:

number of valence electrons they contain.

As you move to the right across a period in the periodic table, ________ decreases.

atomic size

The atomic size of an atom is determined by the distance between:

the outermost electrons and the nucleus.

As you move down a column in the periodic table, atomic size:

increases.

The increase in the number of protons results in a greater pull on the electrons from the nucleus, causing atomic size to:

decrease.

_______ energy increases as you move to the right across a period and decreases as you move down a column in the periodic table.

Ionization

What number represents the speed of light?

3×10⁸

The speed of a wave ( c ) is equal to:

wavelength (λ) times frequency (v)

When calculating energy, h represents:

Planck’s Constant

Planck’s Constant

6.626×10^-34

Energy (J) =

h x v