C. Johannesson

II. Bohr Model of the Atom(p. 94 - 97)

Ch. 4 - Electrons in AtomsCh. 4 - Electrons in Atoms

C. Johannesson

C. Johannesson

Bohr's Atom: Quantum Behavior in Hydrogen

Concept Simulation - reenacts electron's 'jump' and 'fall' to precise energy levels in a hydrogen atom.

Visionlearning Viewer

C. Johannesson

A. Line-Emission Spectrum

ground state

excited state

ENERGY IN PHOTON OUT

Hydrogen Gas

Atoms are “excited”

with an electric current

C. Johannesson

B. Bohr Model

e- exist only in orbits with specific amounts of energy called energy levels

Therefore…

e- can only gain or lose certain amounts of energy

only certain photons are produced

C. Johannesson

B. Bohr Model

1

23

456 Energy of photon depends on the difference in energy levels

Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom

C. Johannesson

C. Other Elements

Each element has a unique bright-line emission spectrum.

“Atomic Fingerprint”

Helium

Bohr’s calculations only Bohr’s calculations only worked for hydrogen! worked for hydrogen!

a) Electronsb) Protonsc) Neutronsd) Both (b) and (c)

According to the Bohr model of the atom, which particles are allowed to exist in any one of a

number of energy levels?

C. Johannesson

a) “jump” from a lower energy level to a higher energy level

b) “jump” from a higher energy level to a lower energy level

c) “jump” from the ground state to an excited stated) None of the above

The line-emission spectrum of an atom is caused by the energies released when

electrons

C. Johannesson

a) has no electronsb) does not release energyc) releases energy of only certain valuesd) can exist only in the ground state

Because excited hydrogen atoms always produce the same line-emission spectum, scientists

concluded that hydrogen

C. Johannesson

a) oneb) twoc) threed) four or more

Bohr’s model correctly explains the spectra of atoms with how many electron(s)?

C. Johannesson

a) absorptionb) emissionc) translationd) regression

The process of an atom releasing energy when it moves to a lower energy state is

called

C. Johannesson

a) In the orbit closest to the nucleusb) In the orbit farthest from the nucleusc) in the electron cloudd) midway between two orbits

In the Bohr model of the atom, in which orbit is an electron in its lowest energy

state?

C. Johannesson

C. Johannesson

Flame test online lab!!!!

http://www.800mainstreet.com/spect/emission-flame-exp.html

http://www.800mainstreet.com/spect/emission-flame-exp.html