General
What is the exponent of SI prefixes of tera, giga, micro and pico?
giga: 10^9
micro: 10^-6
pico: 10^-12
Name the 3 parts of an atom, their location and their charges.
electron - negative
neutron - neutral
Calculate the velocity in m/s of a 2.34 g object with kinetic energy = 46.2 J.
199 m/s
Describe these properties: wavelength, frequency, amplitude
wavelength - the distance between peaks
frequency - the speed of the peaks
amplitude - the height of the peaks
What is the definition of a mixture? What are the types of mixtures?
a combination of 2+ substances where the substances still have their own identity
homogeneous: uniform composition (sugar in water)
heterogeneous: does not have uniform composition (like vinaigrette)
Briefly explain what makes an atom more stable (nuclear stability).
Nuclei with even numbers of protons and neutrons are more stable.
Calculate the frequency of light traveling with a wavelength of 126 nm.
2.38 x 10^15 inverse seconds
A quantum of energy is the smallest packet of energy you can get. For an electron, this is called a photon of energy. E = (Planck's constant)(frequency)
What is the meaning of the word isotope?
Atoms that have equal numbers of protons (same identity) but different numbers of neutrons.
The atomic masses of three neon isotopes are as follows: 20-Ne (90.48%) weighs 19.9924356, 21-Ne (0.27%) weighs 20.9938428, 22-Ne (9.25%) weighs 21.9913831. Calculate neon's average atomic mass.
20.18 amu
Order these as they fall on the electromagnetic spectrum: x rays, UV, radio waves, gamma rays, visible light, infrared.
Gamma, x rays, UV, visible, infrared, radio waves.
Calculate the energy per photon of light with wavelength 575 nm.
3.46 x 10^-19 J
The density of a compound is 8.76 g/mL. What is the mass in kg of a 4 L flask of this compound?
35.0 kg
How many moles of Ni atoms are there in 9.00 x 10^9 Ni atoms?
1.49 x 10^-14 mol
An electron in a certain atom is in the n = 2 quantum level. List the possible values of l and m-sub-l that it can have.
l = 0 or 1, because n-1
m-sub-l = -1, 0 or 1, because goes from -l to +l
What is the Heisenberg uncertainty principle?
we cannot know both the exact momentum and the position of a particle at the same time (equation given on formula sheet)
Carry out the following calculation:
242 lb to milligrams (1 lb = 454 g)
1.10 x 10^8 mg
Name two of the atom discovery experiments, the scientists who did them, and what they found.
JJ Thomson proposed the existence of electrons and calculated the charge to mass ratio of the electron with cathode rays. Millikan used the Oil Drop experiment to find the charge of an electron (and thus the mass of the electron). Rutherford proposed the nuclear model of the atom based on the gold foil experiment (found most of the mass of the atom is in the positive nucleus).
Calculate the wavelength (nm) of the emitted photon when an electron drops from the n = 4 to the n = 3 level in a hydrogen atom.
1.88 x 10^3 nm
which has the greater mass: 173 atoms of gold or 7.5 x 10^-22 moles of silver?
silver