Chapter 2
Define or otherwise identify the following: Photon
Electromagnetic radiation that has neither mass nor electric charge but interacts with matter as though it is a particle; x-rays and gamma rays.
List the fundamental principles within an atom.
Electrons, protons, and neutrons.
Why doesn't an electron spontaneously fly away from the nucleus of an atom?
Electrostatic force of attraction, electron binding energy.
How does carbon 14 dating determine the age of petrified wood?
Fixed 14C in petrified wood decays, while 14C in living wood is replenished.
Define or otherwise identify the following: K shell
Innermost electron shell.
Describe the difference between alpha and beta emission.
Mass and charge on the particle. An alpha particle has four units of mass and two units of positive charge. A beta particle has essentially no mass and one unit of negative charge.
Define or otherwise identify the following: Nucleons
Neutrons and protons.
Define or otherwise identify the following: Chemical compound.
New substance that is formed when two or more atoms of different elements combine.
Who developed the concept of the atom as a miniature solar system.
Niels Bohr.
Can atoms be ionized by changing the number of positive charges?
No. Positive charges (protons) do not move, they are confined to the nucleus.
Figure 2-1 shows the following approximate sizes: an atom, 10^-10 m; the Earth, 10^7 m. By how many orders of magnitude do these objects differ?
17 orders of magnitude - (7- -10) --> (7 + 10) = 17
If atoms large enough to have electrons in the T shell existed, what would be the maximum number allowed in that shell.
200 Electrons - 2n^2
Define or otherwise identify the following: The arrangement of the periodic table of elements.
An arrangement of all known elements into rows and columns. The rows are referred to as a period, and it relates to the number of electron shells present; the columns are referred to as a group, and relate to the number of electrons in the outermost shell.
Describe how ion pairs are formed?
An ion pair is formed when an electron is removed from an atom by ionizing radiation.
Sr 90/38 has a half-life of 29 years. If 10 MBq were present in 1950, approximately how much would remain in 2010?
Approximately 2.5 MBq
How many protons, neutrons, electrons, and nucleons are found in the following: O 17/8, AL 27/13, Co 60/27, Ra 226/88
O (Oxygen) = 8 Protons, 9 Neutrons, 8 Electrons, 17 Nucleons Al (aluminum) = 13 Protons, 14 Neutrons, 8 Electrons, 27 Nucleons Co (Cobalt) = 27 Protons, 33 Neutrons, 27 Electrons, 60 Nucleons Ra (Radon) = 88 Protons, 138 Neutrons, 88 Electrons, 226 Nucleons
For what is Mendeleev remembered?
Periodic table of the elements.
Define or otherwise identify the following: Positron
Positively charged beta particle.
Complete the following table with relative values: α (alpha) β (beta) β+ (positron) γ (gamma) X (x-ray)
TYPE MASS ENERGY CHARGE ORIGIN α (alpha) 4 amu MeV +2 Nucleus β (beta) 0 amu keV -1 Nucleus β+ (positron) 0 amu keV +1 Nucleus γ (Gamma) 0 amu MeV 0 Nucleus X (x-ray) 0 amu keV 0 ElectronShells
What determines the chemical properties of an element?
The arrangements of electrons in the outermost shells.
What property of an atom does binding energy describe?
The energy required to hold nucleons together as a nucleus (nuclear binding energy). The energy required to maintain electrons in orbit about the nucleus (electron binding energy).
Define or otherwise identify the following: The Rutherford atom
The first description of an atom having a nucleus.
Define or otherwise identify the following: Alpha particle
The nucleus of the helium atom—two neutrons and two protons.
Define or otherwise identify the following: Radioactive half-life
Time required to reduce radioactivity to half its original value.
Define or otherwise identify the following: W (chemical symbol for what element?)
Tungsten.
How much more tightly bound are K-shell electrons in Tungsten than (a) L-shell electrons, (b) M-shell electrons, (c) free electrons?
a. 58 keV. b. 67.2 keV. c. 70 keV.