Discovering Design with Chemistry Chapter 3

Define the following terms:

a. Radioactive decay

b. Physical constant

c. Ground state

d. Spectroscopy

a. The spontaneous breakdown of an atom's nucleus, which often changes the element to which the atom belongs.

b. A quantity in nature that never changes

c. The lowest energy state of a particle

d. Identifying chemicals by studying the light they emit or absorb

What is the mass of the average calcium atom in grams?

6.65 × 10^-23 g

A specific isotope of nitrogen has a mass of 2.49x10^-23 g. What is its mass in amu? What would be the symbol (including the mass number) for this isotope?

15.0 amu

How many protons, neutrons, and electrons are in a magnesium-25 atom?

There are 12 protons, 13 neutrons, and 12 electrons in magnesium-25.

An atom has 5 protons, 5 neutrons, and 5 electrons. What is its symbol (including the mass number)?

B-10

What is the most abundant isotope of phosphorus?

P-31

What is the most difficult thing to do when it comes to making a nuclear bomb?

The most difficult thing about making a nuclear bomb is the Isotope Enrichment process.

What do nuclear power plants use to keep a chain reaction from getting out of control?

Nuclear power plants use control rods to keep a chain reaction from getting out of control

List the colors of light in order of wavelength, from longest to smallest.

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Light has a wavelength of 231 nm. What is its wavelength in meters?

2.31 x 10^-7 m

What is the frequency of the light in the previous problem?

1.30 x 10^15 Hz

Light has a frequency of 3.45x10^17 Hz. What is its wavelength?

8.70 x 10^-10 m

To what does the term "electromagnetic waves" refer?

The term "electromagnetic waves" refers to all light waves, whether or not they are visible

Name three categories of electromagnetic waves, other than visible light.

Microwaves, Radio Waves, Long radio waves

A photon has a frequency of 1.94x10^16 Hz. What is its energy?

1.29 x 10^-17 J

A photon has an energy of 1.19x 10^-16 J. What is its frequency?

1.79 x 10^17 Hz

Orange light has a wavelength of 612 nm. What energy does a photon of this light have?

3.25 x 10^-19 J

A photon has an energy of 2.17x10·18 J. What is its wavelength?

9.17 x 10^-8 m

The electron of a hydrogen atom is in the n = 5 orbit. To get back to its ground state, it releases a single photon with a wavelength of 95 nm. If the electron of another hydrogen atom is in its ground state, what wavelength of light must it absorb to get to the n = 5 orbit?

95 nm

The electron of one hydrogen atom moves from the n = 3 orbit directly to its ground state. The electron in another hydrogen atom moves from the n = 2 orbit to its ground state. Which electron released a photon with the longer wavelength? Which released a photon with the higher frequency?

The second photon has the longer wavelength. The first photon has the higher frequency.

What is the key assumption in the Bohr model of the atom?

The key assumption in the Bohr model of the atom is that electrons are only allowed to be in certain orbits around the nucleus.

Fill in the blanks: Atoms are more than 99.999% ___________ ___________.

empty space

Consider the emission spectra shown below:

See Discovering Design with Chemistry Page 96.

If a mixture of two elements has the following emission spectrum:

See Discovering Design with Chemistry Page 96.

what elements are present in the mixture?

Both Hydrogen and Lithium are present in the mixture.