Ch 7- The Nucleus Flashcards
Of the following particles, the one with the greatest mass is the A. Neutron B. Neutrino C. Proton D. Electron
A. Neutron
The Atomic number of the Nitrogen nucleus is? 15/7N A. 15 B. 56 C. 8 D. 7
D. 7
The mass number of Nitrogen is? 15/7N A. 8 B. 56 C. 15 D. 7
C. 15
The number of neutrons in the Nitrogen Nucleus is? 15/7N A. 7 B. 56 C. 8 D. 15
C. 8
The nucleus of a helium atom is called A. an alpha particle. B. a quark. C. a beta particle. D. a gamma ray.
A. an alpha particle
The electromagnetic waves emitted by a nucleus are called A. gamma rays B. ultraviolet rays C. quarks D. X-rays
A. gamma rays.
A particle never emitted in beta decay is the A. electron B. positron C. neutron D. neutrino
C. neutron
A nucleus increases in atomic number when it emits A. a neutron B. a positron C. an electron D. a proton
C. an electron
As a sample of radioactive nuclide decays, its half-life
A. any of the choices, depending upon the nuclide
B. remains the same
C. decreases
D. increases
B. remains the same
The most important single source od radiation dosage received by an average person in the US is A. radon B. nuclear reactors C. radium D. medical x-rays
A. radon
The unit in which atomic masses are usually expressed is the A. gram B. eV C. u D. quark
C. u
An atomic nucleus has a mass that is
A. the same as the total moss of its constituent nucleons.
B. less than the total mass of its constituent nucleons
C. any of the choices, depending on the nucleus
D. more than the total mass od it s constituent nucleons
B. less than the total mass of its constituent nucleons
Slightly enriched uranium can be the energy source of which one or more of the following? A. nuclear fission reactors B. nuclear weapons C. X-rays D. nuclear fusion reactors
A. nuclear fission reactors
Protons and neutrons are held together to form nuclei by the A. strong interaction B. weak interaction C. gravitational interaction D. electromagnetic interaction
A. Strong interaction
The strongest of the fundamental interaction is the A. gravitational interaction B. strong interaction C. electromagnetic interaction D. weak interaction
B. strong interaction
Rutherford’s discovery of the nucleus is summarized and related to
modern atomic theory
The physicist that showed that alpha particles striking a thin metal foil are deflected by the strong electric fields of the metal atoms nuclei
Ernest Rutherford
Rutherford’s experiment resulted in…
- an atom’s positive charge and nearly all of it mass are concentrated in its nucleus
- the atom’s electron, because of their small mass, have little effect on the alpha particles.
- an atom is mostly empty space
Who described atoms as positively charged lumps of matter with electrons embedded in them?
J.J. Thompson
neutrons are what charge?
neutral
Protons are what charge?
Positive
Electrons are what charge?
negative
The number of protons in an atom is the
atomic number
the number of protons equal to what
number of electron
Atoms of the same element that differ in the number of neutrons in their nuclei
isotopes
The nucleus with a particular composition is called
nuclide A/Z X
Number of protons and neutrons in the nucleus
mass number
neutron or proton
nucleon
who discovered radioactivity
Henri Becquerel
penetrating radiation
radioactivity
when a nucleus emits particles or high frequency em waves
radioactive decay
when an alpha particle is emitted from a large, unstable nucleus
alpha decay 4/2He
when very high frequency em waves are emitted by nuclei having excess energy
Gamma decay ( em waves= gamma rays)
in which an electro Is emitted from a nucleus having an unstable neutron to proton ratio; a nuclear neutron changes to a proton and an electron
Beta decay
positively charged electron
positron
the capture of an electron by a nuclear proton changes the proton to a neutron in a nucleus having a high proton to neutron ratio
Electron capture
the time needed for half of an original sample to decay
half-life
SI unit of radiation dosage is
Sv= Sievert
SI unit for atomic mass
u=1.66x10^-27 kg
SI unit for atomic physics
electronvolt(eV)= 1.60x10^-19J
equal to 1 million eV
megaelectronvolt= 1.60x10^-13J
rest mass of 1 u
931 MeV
found by dividing the total binding energy of the nucleus by the number of nucleons it contains
binding energy per nucleon
the greater the binding energy per nucleon=
the more stable the nucleus
series of fission reactions spreading through a mass of an unstable radionuclide such as uranium
Chain reaction
the first chain reaction was demonstrated by the Italian Physicist
Enrico Femi
Moderator
slows down neutrons in a nuclear reactor
an element that has an atomic number greater than the 92 uranium
transuranium element
cannot be separated into other particles
elementary particle
nucleons are composed of smaller particles called
quarks
has the same mass and general behavior as its corresponding elementary particle but has a charge of opposite sign and differs in certain other respects
antiparticle
when an antiparticle and its corresponding elementary particle come together, they undergo
annihilation
process in which a particle- antiparticle pair materializes from energy
pair production
not affected by the strong interaction and have no internal structure
Leptons
leptons that have no charge and very little mass
Neurtrinos
are affected by the strong interaction, are composed of quarks
Hardons
