Unit 3

Question 1

Electromagnetic Spectrum

Answer 1

the full range of electromagnetic radiation, organized by frequency or wavelength

Question 2

En (total energy of nth state)

Answer 2

En= (-2.18 x 10^-18 J)(z^2/n^2)
or
En= (-13.6 eV)z^2/n^2)

Question 3

Z

Answer 3

atomic number, the charge number of an atomic nucleus

Question 4

eV (electric volt)

Answer 4

1.602 x 10^-19 J

Question 5

a0

Answer 5

a0= 52.9 pm
Bohr radius (the most probable distance between the nucleus of a hydrogen atom and its single electron when the atom is in its ground state (lowest energy level))

Question 5

pm

Answer 5

1 x 10^-12 m

Question 5

rn

Answer 5

-rn= (n^2/z) x a0
-radius of orbit of electron when atom is in nth state

Question 6

spectrum of incoming light

Answer 6

the distribution of different wavelengths of light (colors) that are hitting a substance

Question 7

distinct energy

Answer 7

the concept that electrons in an atom can only occupy specific, fixed energy levels, meaning they can only have certain distinct values of energy, not a continuous range of energies

Question 8

line in spectrum

Answer 8

each line represents a unique λ

Question 9

spectrum of elements

Answer 9

each element has a unique spectrum

Question 10

Bohr’s model of the atom

Answer 10

-atoms exist in discrete or quantized states
-these energy states are described by a quantum number (n=1, 2, 3,…)
-atom transitions between energy states in quantum leaps
-energy is conserved, the energy of the quantum leap is the energy of the photon emitted or absorbed by the atom
-Bohr’s energy equation is applied to one electron atoms/ions
-total energies of bound states are negative and conserved

Question 11

quantum leap

Answer 11

a huge, often sudden, increase or advance in something

Question 12

emission

Answer 12

-Eph= -∆E(atom)
-atom loses energy
-atom becomes more stable

Question 13

absorption

Answer 13

-Eph=∆E(atom)
-atom (ion) gains energy
-atom becomes less stable

Question 14

binding energy

Answer 14

the amount of energy needed to completely remove an electron from its orbit around the nucleus

Question 15

first excited state

Answer 15

On the energy level diagram of a system, the state immediately above the ground state

Question 16

ground state

Answer 16

The state of lowest energy for an atom, molecule, or collection of molecules

Question 17

Å (angstrom)

Answer 17

1 x 10^-10 m

Question 18

bound system

Answer 18

• -E(tot)
  -a collection of atoms or molecules held together by attractive forces, where the total energy of the system is negative