TAT/ALC Physical Science Module 13 (Apologia)
The half-life of the man-made isotope C-11 is 20 minutes. If a scientist makes 1 gram of C-11, how much will be left in one hour?
0.125 g
nucleus
the center of an atom, containing the protons and neutrons
Neon-20 has 10 protons. How many electrons and neutrons does it have, respectively?
10, 10
The element sodium is made up of all atoms with 11 protons. How many protons, electrons, and neutrons are in a sodium-23 atom, respectively?
11, 11, 12
Mg-24 has 12 protons. How many electrons and neutrons does it have, respectively?
12, 12
Two atoms are isotopes. The first has 18 protons and 20 neutrons. The second has 22 neutrons. How many protons does the second atom have?
18
The half-life of the radioactive decay of Ra-226 is 1600 years, If a sample of Ra-226 originally had a mass of 10 grams, how many grams of Ra-226 would be left after 3,200 years?
2.5 g
How much more massive are protons than electrons?
2000 times
Fe-56 has 26 protons. How many electrons and neutrons does it have, respectively?
26, 30
Carbon dating is really only reliable for things ___ years old and younger because tree rings are used for analysis.
3,000
How many electrons are in the largest Bohr orbit in uranium (92 protons)?
32
An atom has an atomic number of 34. How many protons and electrons does it have?
34
La-139 has 57 protons. How many electrons and neutrons does it have, respectively?
57, 82
A uranium atom has 92 protons. What is its largest Bohr orbit?
5th
How does gamma decay work?
A radioactive isotope emits a gamma ray, a high-energy photon.
model
A schematic description of a system that accounts for its known properties
How does alpha decay work?
An unstable nucleus reduces its number of neutrons and protons by ejecting a He-4 nucleus, or alpha particle.
Why is radioactive dating unreliable in most situations?
Assumptions must be made as to the original condition of the object. These assumptions are usually erroneous.
Who discovered pions and gave a rough prediction of their mass?
Hideki Yukawa
Determine the daughter product produced in the beta decay of Te-98 (Use periodic table)
I-98
How does beta-plus decay work?
Neutron-deficient nuclei tend to decay by positron emission or electron capture. Positron emission refers to the emission of a positron along with a neutrino and the resulting conversion of a proton inside the nucleus into a neutron.
Is the Bohr model completely correct?
No
Is a neutron stable on its own?
No; If it is not in the nucleus of an atom, it will decay into a proton, an electron, and an antineutrino in a matter of minutes.
How does beta-minus decay work?
Nuclei that are rich in neutrons tend to decay by emitting an electron along with an antineutrino. As a result, one of the neutrons in the nucleus changes into a proton.
All atoms with eight protons are oxygen atoms. If a particular oxygen atom has eight neutrons, what is its name and how many electrons does it have?
Oxygen-16, 8
Determine the daughter product produced in the alpha decay of Ra-224 (Use periodic table)
Rn-220
An atom has an atomic number of 34. What is its chemical symbol? *Use periodic table
Se
Why is the strong nuclear force such a short-range force?
Since pions have a very short lifetime, the force can only act over very tiny distances.
Which of the following atoms are isotopes? Cd-112, Sn-112, Xe-120, Ar-40, Sn-120
Sn-112 and Sn-120
Determine the daughter product produced in the alpha decay of Bi-212 (Use periodic table)
Tl-208
Determine the daughter product produced in the beta decay of I-125 (Use periodic table)
Xe-125
Can a radioactive isotope be ignored if it is small enough?
Yes
element
a collection of atoms that all have the same number of protons
People who regularly work with large samples of radioactive isotopes sometimes wear special suits lined with a thin layer of lead or other heavy material. What kinds of radiation are these people mostly protected against when wearing a suit?
alpha and beta particles
List the three types of radioactive particles discussed in the module in the order of their ability to travel through matter. Start with the particle that cannot pass through much matter before stopping and end with the one that can pass through the most matter before stopping.
alpha particles, beta particles, gamma rays
radioactive isotope
an atom with a nucleus that isn't stable
isotope
atoms with the same number of protons but different numbers of neutrons
Order the constituent parts of the atom in terms of their mass from least to most massive.
electron, proton, neutron
What is an atom mostly made of?
empty space
A radioactive isotope goes through radioactive decay, but the isotope's number of protons and neutrons does not change. What kind of radioactive decay occurred?
gamma decay
The strong force is also manifested in the exchange of ___ between ___
gluons, quarks
Suppose a new force is discovered, and scientists determine that it is governed by the exchange of a particle known as the "wileon". If the lifetime of a wileon is greater than that of a pion but shorter than that of a photon, what is the range of this new force relative to the range of the range of the nuclear force and the electromagnetic force?
longer than nuclear force but shorter than electromagnetic force
Do neutrons have a charge?
no, they are neutral
Atoms are made up of
protons, neutrons, electrons
What is the more correct model of an atom called?
quantum-mechanical model
What force keeps the protons and neutrons in the nucleus?
strong nuclear force
What force keeps the electrons orbiting around the nucleus?
the electromagnetic force
What causes the strong nuclear force?
the exchange of pions between protons and/or neutrons
atomic number
the number of protons in an atom
The nuclear force is a manifestation of what force?
the strong force
mass number
the sum of the number of neutrons and protons in the nucleus of an atom
half-life
the time it takes for half of the original sample of a radioactive isotope to decay
What governs radioactivity?
the weak force
