Physics ch. 20
State the number of protons in nuclei 238/92 U
92
T/F: Pure elements can be transformed into entirely different elements. This statement at the present time is
T
An atom with an imbalance of electrons to protons is a. an ion b. an isotope c. a hadron d. a baryon e. none of these
a
Carbon 14 is produced in the atmosphere principally by a. cosmic ray bombardment b. plants and animals c. nitrogen bombardment d. photosynthesis e. none of these
a
Different isotopes of an element have different numbers of a. neutrons b. photons c. protons d. hadrons e. none of these
a
Suppose 2 kg of a material has a half-life of 1 day. After how long will NONE of the material remain? a. Never b. after 1 day c. after 2 days
a
Suppose the half-life of a material is 10 days. You have one 1 kg of the material today. How much of the material would you have after 10 days and 20 days, respectively? a. 0.5 kg after 10 days, and 0.25 kg after 20 days b. 0.5 kg after 10 days, and the same after 20 days c. 0.5 kg after 10 days, and none after 20 days
a
The atomic number of an element is the same as the number of its a. protons b. nucleons c. neutrons d. neither of these
a
The mass of an atomic nucleon is nearly a. two thousand times the mass of an electron b. a thousand times the mass of an electron c. twice the mass of an electron d. four times the mass of an electron
a
There is a greater proportion of carbon 14 in a. new bones b. old bones c. the same in each
a
A material has a half-life of 1 day. If 2 kg of this material is available today, how much of it was available yesterday, and how much the day before? a. 2 kg yesterday, and 2 kg the day before b. 4kg yesterday, and 8 kg the day before c. 3 kg yesterday, and 4 kg the day before
b
Electric forces within an atomic nucleus tend to a. hold it together b. push it apart c. neither of these
b
Most of the radioactivity we personally encounter comes from a. medical X rays b. the natural environment c. nuclear power plants d. fallout from past and present testing of nuclear weapons
b
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 a. 11,500 years. b. 17,200 years. c. 716 years. d. 22,900 years. e. 46,000 years.
b
When a gamma ray is emitted by a nucleus, the nucleus then has less a. charge b. energy c. both of these d. neither of these
b
Which of the following isotopes is radioactive a. carbon 12 b. carbon 14 c. both are radioactive d. neither are radioactive
b
Which radiation has no electric charge associated with it? a. alpha rays b. gamma rays c. beta rays d. all of these e. none of these
b
X-rays may be regarded as a. high frequency sound waves b. high frequency radio waves c. both of these d. none of these
b
When a nucleus emits a beta particle, its atomic number a. changes, and so does its mass number b. remains constant, and so does its mass number c. changes, but its mass number remains constant d. remains constant, but its mass number changes e. none of these
c
When an alpha particle is ejected from a nucleus, the nucleus the has less a. mass b. charge c. both of these d. neither of these
c
Which of these is electromagnetic radiation? a. debris of nuclear decay b. alpha radiation c. gamma radiation d. beta radiation
c
X-rays are most similar to which of the following: alpha, beta or gamma rays? a. alpha b. beta c. gamma
c
Carbon dating requires that the object being tested contain a. inorganic material b. sugar molecules c. charcoal d. organic material e. none of these
d
A certain radioactive isotope placed near a Geiger counter registers 120 counts per minute. If the half-life of the isotope is one day, what will the count rate be at the end of four days? a. 10 counts/min b. 5 counts/min c. 15 counts/min d. 30 counts/min e. 7.5 counts/min
e
A device that is used primarily to detect nuclear radiation is a a. synchrotron b. linear acceleration c. cyclotron d. all of the above e. none of the above
e
The half-life of a radioactive substance is independent of a. the number (if large enough) of atoms in the substance b. whether the substance exists in an elementary state or in a compound c. the age of the substance d. the temperature of the substance e. all of these
e
State the number of neutrons in nuclei 2/1 H
1
State the number of protons in nuclei 2/1 H
1
State the number of neutrons in nuclei 238/92 U
146
State the number of protons in nuclei 56/26 Fe
26
State the number of neutrons in nuclei 56/26 Fe
30
State the number of neutrons in nuclei 12/6 C
6
State the number of protons in nuclei 12/6 C
6
