Chemistry Unit 4- Electrons in atoms

Describe the relationship between wavelength and energy of light?

As the wavelengths get shorter, energy of light increases.

Speed of light is represented by which letter?

C

What causes the color of the beam of photons to change?

Changing the wavelength

Interference

Combining energy of 2 different waves in the same area. 1. Destructive- 2 waves cancel each other out 2. Constructive- 2 waves add together

For an electron to move from an energy level far from the nucleus to one close to the nucleus it would need to _____ an electron

lose

Wavelength is represented by what?

lamtha symbol in meters or nanometers

Photoelectric effect

-refers to the emission of electrons from a metal when light shines on the metal -no electrons emitted if the lights frequency is below a certain minimum regardless of the lights intensity -wave theory of light predicted that light at any frequency could eject an electron

Particle theory of light/ Planck

-studying emission of light by hot objects; proposed that hot objects do not emit energy continuously as the would if emitted in the form of waves - Planck suggested that objects emit energy in small packets called quanta -proposed e=hv and 6.626X10^-34 js

1 meter= _______ nm

1 X 10 ^9

what is an orbital?

3-d region where electrons are most likely found

Explain why a single atom of hydrogen cannot produce all four hydrogen spectral lines simultaneously.

A single atom only has one electron so it can't have all four transitions at the same time.

Aufbau Principle

According to this principle, electrons fill orbitals starting at the lowest available energy states before filling higher states

Why can there be different shades of reds, blues, etc.?

Different wavelengths have different shades.

What type of relationship is there between frequency and energy?

Direct

Bohr said the electron cloud is mostly _________.

Empty space.

Which state is this: energy is absorbed and atoms move to a *higher* level.

Excited state.

For an electron to move from an energy level close to the nucleus to one far from the nucleus it would need to _____ an electron

Gain

Which state is this: Electrons fall back to the *initial* energy level and release a photon.

Ground state

Which letter is associated with 6.626 X 10 ^-34?

H in Js

What type of relationship is there between wavelength and energy?

Inverse

The lager the electron transition, the ______ energy.

More

Do all colors have the same energy? If no, which colors have the highest and lowest energy?

No, blue and violet have the most while red has the least amount of energy.

Does a gas discharge tube filled with boron emit the same wavelengths of light as a tube filled with hydrogen?

No, hydrogen produces different wavelengths than boron, and therefore they have different shades of color.

Which color has the longest wavelengths?

Red (least energy)

Energy is ____ as electrons move to a lower state.

Released

Heisenberg stated that, it is impossible to know what 2 things about an electron?

Speed and location

What happens to light when it passes through a prism?

The light is split into colors

How can we see all four colors from a hydrogen gas discharge tube simultaneously?

There are millions go hydrogen atoms filling the tube. Each one can have a different transition occurring, so all the colors are represented by the atoms present.

Each element as a ________ set of spectral lines.

Unique. (think fingerprints for humans)

Frequency is represented by what symbol?

V in hertz

Which color has the shortest wavelengths?

Violets (most energy)

Explain the process by which light is emitted by an atom

When an atom moves from excited state to ground state and it emits a photon, creating light

Photon

a particle of electromagnetic radiation having zero mass and carrying a quantum of energy

Energy is _____ as electrons move to a higher state.

absorbed

As an electron gets closer to the nucleus the _______ to the nucleus gets ______

attraction; stronger.

Diffraction

bending around an edge

Hund's rule

describes how electrons are distributed among orbitals of the same sub level when there is more than one way to distribute them. Each orbital of the same sub level have one electron and all have the same spin.

The Pauli Exclusion principle

describes the restriction on the placement of electrons into the same orbitals. "If two electrons occupy the same orbital, they must have opposite spins."

d

double dumbell

P

dumbbell align on x, y, z, axis

Electrons absorb energy from various sources, such as ______, when they move from lower energy levels, or _______ to higher energy levels, or _______.

electricity; ground state; excited state.

explain the process by which an atom emits a photon?

electrons absorb energy and move from ground state to excited state, producing a photon when it returns to ground state.

Quantum

energy is the minimum quantity of energy that can be lost or gained by an atom

What happens to frequency as you increase wavelength?

frequency decreases

Higher frequency= _____ energy

higher

S

spherical

Heisenberg Uncertainty Principle

states that it is impossible to determine simultaneously both the position and the velocity of an electron or any other particle

Do all colors travel at the same speed? If yes, what is it?

yes, 3.00 X 10 ^8 m/s