Nuclear Physics Final

There is only one stable isotope of aluminum. How many neutrons would you guess this isotope has?

14

Rutherford was born in the fringes of the British Empire, in what country?

New Zealand

Radiocarbon dating depends on living tissue having what radioactive isotope?

Carbon-14

Which term did Soddy use to describe elements with the same atomic number Z but with different masses?

Isotopes

In 1920 Aston proposed what masses of all elements have whole number relationships to oxygen-16. This is called the what rule?

Whole-number rule

In 1932 Chadwick discovered this particle, which is now known as a nucleon.

Neutron

If a nucleus in a magnetic field has a magnetic energy given by U = ±mu * B(vector), then mu(vector) is said to be its ______.

magnetic moment

What element/isotope that the highest binding energy per nucleon (~8.8 MeV)

Iron-56

If you plot N vs Z for stable isotopes, what is the (approximate) slope in the Z<16 region?

1

The quantity defined by R = |dN/dt| is called _____.

Activity

The unit 1 decay/second is often called the ____.

Becquerel

I have a gram of radioactive material. After two half lives have transpired, how much do I have left?

¼ gram

Tiny neutral particles, almost (but not quite) zero mass, discovered in 1956.

Neutrinos

He first explained the strong force (1935) and proposed the existence of mesons.

Yukawa

The term in the semi-empirical E_b formula that penalizes nuclei with large Z is called the ____ term.

Coulomb

Goeppert-Mayer and Jensen worked out the shell model of the nucleus in 1950, which helped explain ____.

Why even-even nuclei are prevalent

Rutherford’s gold foil experiment showed that most alpha particles passed through the foil because ____.

Gold atoms are made of mostly empty space

How many neutrons do you expect C-14 to have?

8

What is the daughter from the beta minus decay of U-238

Np-238

What is the daughter from the alpha decay of Pu-242

U-238

What is the daughter from the beta plus decay of B-8?

Be-8

What three things are evidence for atomic theory? (in 1899)

Crystal structure, chemistry law of multiple proportions, and stat mech

What is the law of multiple proportions?

Elements that mix to form compounds do so in specific whole-number ratios

Why is stat mech evidence for the existence of atoms

The fact that statistical mechanics works is evidence that atoms exist.

What are the three early models of the atom and who made them?

Democritus’s little Doritos
Tiny indestructible spheres (Dalton)
Plum Pudding Model (Thomson)

What did the Rutherford experiment find?

The positive charge was concentrated in a tiny region called the nucleus.

What does Z represent and where is it in nuclear notation?

Atomic number, number of protons, and is on the bottom left of the element symbol.

What does A represent and where is it in nuclear notation?

Mass number, number of protons plus neutrons, top left of the element symbol.

A ______ is a nucleus with a particular Z and N.

Nuclide

What is the nuclear notation for a neutron, photon, alpha particle, and electron?

1 0 0 4 0 -
n lambda alpha e
0 0 2 -1

Nuclear magnetic moments precess in magnetic fields, at the a frequency ________.

Lamour frequency

In 1936, Gamow, proposes the ____________ to quantify the binding energy/nucleon graph

Liquid drop model

What are even-even nuclei and why are 58% of all stable nuclei?

They are nuclei with an even number of protons and neutrons. They are more common because stability is maximized if nucleons pair up/spin down.

Who discovered radioactivity initially?

Becquerel

What materials did the Curies discover radioactivity in?

Polonium and radium

What is another term for radioactivity?

Ionizing radiation

What device was made in 1928 to detect any kind of ionizing radiation?

Geiger-Müller tube

What device was created in 1944 by Samuel Curran to detect radioactivity?

Scintillation counter

What are the units of activity rate (R)

1 decay/s or 1 Bq

What is lambda in R=(lambda)*N

Decay constant, in units of Bq

What is the half-life of C-14?

5730 yrs

What is the ratio of C-14 atoms to C-12 atoms in living creatures?

1.3×10^-12

Isotopes that predate the Earth are called

primordial isotopes/primordial nuclides

All 251 stable isotopes primordial

True

All 35 radioactive isotopes are primordial and called

Primordial radionuclides

What is alpha decay?

A nucleus emits an alpha particle and daughter nucleus. (Z,A) → (Z-2, A-4)

What is beta minus decay?

A neutron inside the nucleus decays into a proton and an electron is emitted. A beta minus particle is an electron. (Z,A) → (Z+1, A) + e^-

What is beta plus decay?

Proton → neutron and anti-electron is emitted. A beta + particle is an anti electron. (Z,A) → (Z-1, A) + e^+

What is gamma decay?

An excited nucleus emits a gamma particle (high energy photon). (Z,A)* → (Z,A)

A ________ is a metastable state of an atomic nucleus, in which one or more nucleons occupy the excited state levels.

nuclear isomer

What does activity measure and what is a unit?

How often a nucleus decays. Bq

What does absorbed dose measure and what is a unit?

Energy absorbed by living tissue per unit mass. (Not good for assessing risk) Gray, or 1J/kg

What does equivalent dose measure and what is a unit?

The energy absorbed by living tissue per unit mass, taking into account the relative dangerousness of different kinds of radioactivity. Sievert: 1J/kg

A ______, also called a dosimeter, contains material sensitive to ionizing radiation.

Dosimeter badge

How do deterministic effects of ionizing radiation effect living things and what is an example?

Severity increases with dose.
Reliably happens above a certain threshold.
Acute radiation syndrome

How do stochastic effects of ionizing radiation effect living things and what is an example?

Severity is independent of dose.
Probability increases with dose.
Cancer

How does radiation cause cancer?

Radiation source interacts with cells causing DNA damage. A cancer cell forms and spreads into a tumor.

_______ means the process by which a developing baby (embryo or fetus) develops birth defects

Teratogenesis

In 1934, ______ _________ saw a faint blue-ish light around a uranium salt solution under water, this is _______ radiation

Pavel Cherenkov
Cherenkov