Light & Waves
What is the distance from one wave crest to the next called?
wavelength
What small part of the electromagnetic spectrum can human eyes detect?
Visible light
What word means a tiny packet of electromagnetic energy that can be absorbed or released by matter?
photon
What physicist proposed that electrons occupy specific allowed energy levels around the nucleus?
Niels Bohr
What determines the identity of an element?
Its number of protons.
What measures the number of wave cycles that pass a point each second?
Which has the longer wavelength: red light or violet light?
Red light
What word describes something that can exist only in specific amounts rather than every possible value?
quantized
What is the lowest possible energy level of an electron called?
The ground state
What term describes an atom with equal amounts of positive and negative charge?
Neutral
What unit is used to measure frequency?
hertz (Hz)
Put these in order from longest to shortest wavelength: infrared, radio, visible, and ultraviolet.
Radio → infrared → visible → ultraviolet
What is the movement of an electron from one allowed energy level to another called?
Transition
What term describes energy that can exist only in specific allowed amounts?
Quantized
An isotope has a mass number of 23 and an atomic number of 11. How many neutrons does it contain?
12 neutrons
If the wavelength of light decreases, what happens to its frequency?
The frequency increases.
Which has the greater frequency: an X ray or a microwave?
An X ray
What is the study of how matter interacts with light and how those patterns can reveal what matter contains?
Spectroscopy
Why is a staircase a useful model for electron energy levels?
Electrons can occupy specific allowed energy levels like a person can stand on specific steps, but they cannot exist between those levels.
Two atoms each contain 8 protons, but one has 8 neutrons and the other has 10 neutrons. What is their relationship?
They are isotopes of the same element.
Wave A has a longer wavelength than Wave B. Which wave has the greater frequency and energy?
Wave B has the greater frequency and energy.
Two types of electromagnetic radiation are compared. Radiation A has a shorter wavelength than Radiation B. Compare their frequency and energy.
Radiation A has a higher frequency and higher energy.
What term means an average in which values that occur more often have a greater effect on the final result?
Weighted average
Hydrogen produces only certain spectral lines instead of every possible color. What does this reveal about electron energies?
Electron energies are quantized, so only specific transitions between allowed energy levels can occur.
An element has two isotopes: one has a mass of 10 amu and 20% abundance, while the other has a mass of 11 amu and 80% abundance. What is its weighted average atomic mass?
10.8 amu