Chapter 4

Light is

Electromagnetic radiation

Wavelength is

the distance from on one wave to the same point of the next wave and is used describe electromagnetic waves. It is usually measured meters or nanometers.

red light has a wavelength of

about 700 nm

Wavelengths longer than 700 nm fall into the

infrared region

Violet light has a wavelength of about

400 to 370 nm

Wavelengths shorts than 400 to 370 nm fall into the

ultraviolet (UV) region

Frequency

the number of waves that pass through a point in one second

hertz

A frequency of one wave cycle per second

he energy of a photon of light depends on its

frequency and wavelength

Flame test

Observe colors emitted by different metal ions

spectral lines

colors of only certain energies

Scientists often use _______________ as “fingerprints” to identify elements

line spectra

Photoelectric effect

light causes atoms to eject electrons

The Bohr Model

• Electrons orbit the nucleus

• Only certain orbit energies are “allowed”

• Electrons can jump between levels

  • Light is absorbed or released when electrons jump

When an electron ____________ light, it jumps to a higher energy level

absorbs

When it drops a lower energy level, it ______________ that energy as light

releases

If electrons jump to higher levels, the atom is in the ______________

excited state

Ground state

all electrons in lowest possible levels

if the electron drops from level 5 to level 2, it releases energy in the form of a photon of _________

blue light

As it dropped from level 2 to level 1, it releases ___________

ultraviolet light

Nuclear fusion

The reason the sun gives off light

Specialized cameras can convert infrared energy into visible images, making it possible to “see” someone in the dark. This technique is called ________________

infrared imaging or thermal imaging

The quantum model, which describes ____________

electrons both as particles and as waves

quantum mechanics

A field of study that deals with the unique and surprising behavior of subatomic particles

____________ introduced a startling idea called the uncertainty principle

Werner Heisenberg

One of the key ideas of the uncertainty principle is that __________

it is impossible to precisely know the exact velocity and location of a particle

A second principle of quantum mechanics is ______________

When dealing with tiny particles (such as electrons), we can’t describe them simply as particles - many of their behaviors more closely resemble energy waves

Energy and sublevel rules

1. Electrons occupy different energy levels

2. Each energy level contains one or more sublevels

3. Each sublevel contains one or more orbitals

4. Each orbital holds up two electrons

the ___________ tells us the number of electrons present in any neutral atom

atomic number

Hund’s Rule

If empty orbitals of the same energy are available, electrons singly occupy orbitals rather than pairing together

Valance Level

The highest occupied electron energy level

* Up to 8 electrons in valence level

____________ involve the gain, loss, or sharing of electrons

Chemical changes

Octet Rule

An atom is stabilized by having its highest - occupied (valence) energy level filled

ions are particles with __________

an overall positive or negative charge

Isoelectronic

they have the same electron configurations

elements exhibit similar behavior when _______

their electron configurations are similar

For any atom, we can determine its highest occupied electron energy level from _________

the row it occupies on the periodic table

The right - hand main group block contain elements with _________

highest energy electrons in a p sublevel

The transition elements have outer electron configurations corresponding to ________

d1 to d10

The inner transition elements have out electron configurations corresponding to ______

f1 to f14