Chapter 33
the half-life of carbon-14 is 5730 years. If a 1-gram sample of old carbon is 1/8 as radioactive as 1-gram of a current sample, then the age of the old sample is about
17,200 years
When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number
86
which of the following isotopes is radioactive?
Carbon-14
Generally speaking, the larger a nucleus is, the greater its
Instability
The discovery of radioactivity closely followed the discovery of what?
X-rays
An element that undergoes radioactive decay becomes
an entirely different element
an atom with an imbalance of electrons to protons is
an ion
if an alpha particle and a beta particle have the same energy, which particle will penetrate farther into an object?
beta particle
When an alpha particle is ejected from a nucleus, the nucleus then has less
both of these
When a nucleus emits a beta particle, its atomic number
changes, but its mass number remains the same
Which of these ejects the greatest amount of dangerous radiation into the atmosphere?
coal-fired power plants
The sources of X-rays and gamma rays, respectively, are
electron clouds and the atomic nucleus
When a gamma ray is emitted by a nucleus, the nucleus then has less
energy
Which type of radiation - alpha, beta, or gamma - predominates within an enclosed elevator defending into a uranium mine?
gamma
Which of these is electromagnetic radiation?
gamma radiation
Which radiation has no electric charge associated with it?
gamma rays
X-rays are most similar to which of the following - alpha, beta, or gamma rays?
gamma rays
X-rays are similar to
gamma rays
X-rays may be regarded as
high frequency radio waves
All the uranium in todays deposits in the future will become
lead
the fate of then worlds uranium supply is to eventually become
lead
Different isotopes of an element have different numbers of
neutrons
Is there a greater proportion of carbon 14 in old or new bones?
new bones
Carbon-14 in the atmosphere is transformed from
nitrogen
when thorium (A=90) emits a beta particle, the resulting nucleus has atomic number? 89 90 92 88
none of these
Which of these makes up the least radiation in the everyday environment?
nuclear power plants
the atomic mass number of an element is the same as the number of its
nucleons
If a certain isotope has a radioactive half-life of 10 years, hoe much of the isotope will remain at the end of 20 years?
one quarter
the half-life on an isotope is one day. At the end of three days, how much of the isotope remains?
one-eighth
the strong force is one of the four fundamental forces in nature, and exist
only between particles in the nucleus
Carbon dating requires that the object being tested contain
organic material
the atomic number of an element is the same as the number of its
protons
Electric forces within an atomic nucleus tend to
push it apart
When a beta particle is ejected from a nucleus, the nucleus then has slightly
smaller mass and significantly greater charge
its impossible for a hydrogen atom to emit an alpha particle
true
the mass of an atomic nucleon is nearly
two thousand times the mass of an electron