64 terms

atomic nucleus radio activity test

the nucleus of an atom consists of
protons and neutrons
the force that holds the nucleus together is the
strong force
x-rays are similar to
gamma rays
electrical forces within an atomic nucleus tend to
push it apart
generally speaking, the larger a nucleus is, the more it is
which of the following is Not emitted in radioactive decay
alpha particles, electrons, high-energy electromagnetic radiation, beta rays
when alpha and beta rays pass through a magnetic field, their paths change
in opposite directions
an alpha particle consists of
two protons and two neutrons
the type of radiation that will penetrate farthest into a material is
a gamma ray
the reason alpha rays are easy to stop is that they
are relatively big, are doubly charged, slow down easily
which radiation has no electric charge associated with it
gamma rays
two common products of unbound neutron decay are
a proton and an electron
which experiences the least electrical force in an electric field
a gamma ray
which experiences the greatest electrical force in an electric field
an alpha particle
an atom is called an ion if there
is an even number of protons and electrons
the atomic number of an atom or ion refers to the number of
the atomic mass number of an atom refers to the number of
is an isotope of hydrogen, is stable, consists of one proton and one neutron, can become part of a molecule called heavy water
large nuclei like uranium are radioactive because
there are too many isolated neutrons
the time needed for half of a radioactive sample to decay is called its
the half-life of a certain isotope is 1 day. at the end of 2 days how much of the isotope remains
one quarter
the half-life of most radioactive isotpes is about
half lives range from very short to very long
artificially induced radioactive elements generally have relatively
short half lives
carbon-14, an isotpe of carbon, is formed mostly in
the earth's atmosphere
carbon-14 is radioactive and decays into
nitrogern- 14
the reason carbon dating works is that
after a plant or animal dies, it stops taking in fresh carbon-14
the radioactive tracers can be used to help
farmers use the proper amount of fertilizer, doctors trace food as it moves through the body, engineers how parts of a car withstand age, and public utility workers trace leaks in buried pipes
carbon-14 is produced in the atmosphere primarily by
cosmic ray bombardment
carbon dating requires that the object being tested contain
organic material
most radiation in the air comes from
cosmic ray and earth minerals
a sample of radioactive materials is
somewhat warmer than its surroundings
when a nucleus emits a beta particle, its atomic number
changes but its mass number remains constant
when uranium (92 protons) ejects an alpha particle, the nucleus left behind has
90 protons
when thorium (90 protons) ejects a beta particle, the resulting nucleus has
none of the above
all elements beyond uranium in the periodic table
have no isotopes
when a nucleus emits a positron, its atomic number
decreases by 1
an element will decay to another element with higher atomic number in the periodic table if it emits
a beta particle
in order for an atom to decay to an element that is one greater in atomic number, it can emit
1 alpha particle and 3 beta particles, 1 positron and 2 beta particles, 1 beta particle
an element emits 1 alpha particle and 3 beta particles. its atomic number
increases by 1
you should limit the amount of extra radiation to which you are exposed, because
radiation is harmful to the body, the body can only handle certain amount of radiation in one lifetime, radiation disrupts the body's intricately structured cell system
an experimenter finds that 50% of a sample of uranium-238 has decayed. since uranium-238 has a half-life of 4.5 billion years, the sample's age is about
4.5 billion years
a sample of a certain radioactive material has a half-life of 1 year. how much of this radioactive material will be left at the end of 3 years
one eighth
the half-life of carbon-14 is 5730 years. suppose a basket was found that contains one half as much carbon-14 as a new basket of the same material. what is the approximate age of the basket
5730 years
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
17190 years
a certain radioactive isotope placed near a geiger counter registers 160 counts per second. eight hours later, the counter registers 10 counts per second. what is the half-life of the isotope
8 hours
a certain radioactive isotope placed near a geiger counter registers 120 counts per minute. if the half-life of the isotope is 1 day, what will the count rate ve at the end of 4 days
7.5 counts/min
the nucleus of an atom consists of small particles called nucleons
the mas of an atom is distributed equally among the protons, neutrons, and electrons
nucleons are bound to each other by an attractive force called the nucleon force
neutrons are stable particles and can last for millions of years by themselves without spontaneously decaying
alpha rays are charged positively
it is impossible for a hydrogen atom to emit an alpha particle
of the three major kinds of radioactivity, gamma rays can penetrate the farthest into a material
an ionized atom has the same number of protons a electrons
all elements except hydrogen have isotopes
the atomic number of an element is the same as the number of protons in the nucleus of an atom of that elelment
all isotopes are radioactive
the half-life of an isotope is the time needed for half its mass to change to energy
the changing of one element into another is called transmutation
uranium is the heaviest naturally occurring element normally found in the earth's crust
archeologist use a technique called carbon dating to establish dates of bones and wooden artifacts
everyday plants take in some radioactive carbon-14 through carbon dioxide
uranium dating is another way to date materials, but it is limited to rocks that have been formed only recently in the history of the earth
two round-trip flights between New York and San Francisco normally expose you to as much radiation as a single chest X-ray