Inv 1 Exp 3 - The Bohr Atom - Day 1

A neutral atom of oxygen contains 8 electrons. How many electrons are on its outer energy level of oxygen when it is on its ground state?

• 4

• 8

• 6

• 0

Answer explanation

Two energy levels are used in the ground state. The first level holds 2 electrons. The second level can hold up to 8 electrons, but only 6 are needed for Oxygen.

What does ground state mean for the electron configuration of an atom?

• That the electrons have the lowest possible energy that they can have.

• That all the electrons are on the first energy level (ground floor), which has the lowest energy.

An atom is found to have 9 electrons on three energy levels: 2 in n₁ (first level) , 6 in n₂ (second level), and 1 in n₃ (third level). Is this atom in an excited state? Why or why not?

• It is in an excited state. The ground state allows 8 electrons on the second level. One electron in this atom on the third level even though the second isn't full.

• It is on the ground state since the ground energy level (n₁) is full.

For the atom in the specific excited state as shown in the picture, what possible electron transitions of those below would lead to emission of light? Select all that apply

• Electron moving from the 3rd energy level to the 2nd

• Electron moving from the 1st energy level to the 4th.

• Electron moving from the 4th energy level to the 2nd

• Electron moving from the 1st energy level to the 3rd.

Answer explanation

Only transitions from higher energy levels to lower energy levels lead to emission of energy as photons.

The gap in energy levels is smaller between the higher energy levels than between the lower energy levels. Which photon would have more energy for a given atom?

• A photon emitted when an electron goes from principal energy level 5 to principal energy level 3.

• A photon emitted when an electron goes from principal energy level 1 to principal energy level 5.

• A photon emitted when an electron goes from principal energy level 3 to principal energy level 1

• A photon emitted when an electron goes from principal energy level 2 to principal energy level 1

Answer explanation

Both transitions from 3 to 1 and 5 to 3 involve two energy levels, but the energy gaps are smaller between the higher energy levels.

LAB SAFETY QUESTION:

Flammable Materials such as alcohol should never be dispensed or used near

• an open door

• an open flame

• another student.

• a sink

What is still confusing? How can I help?