Exam 3- chapt 12-16 Flashcards
binding energy
the energy needed to remove a proton or neutron from a nucleus
radioactivity
spontaneous release of energy as certain atoms disintegrate. the emission of one or more kinds of radiation from an isotope with unstable nuclei.
radioactive decay
the process of spontaneous change of unstable isotopes
alpha decay
the loss by an atom’s nucleus of a large and massive particle composed of two protons and two neutrons
beta decay
a kind of radioactive decay in which a particle such as the neutron spontaneously transforms into a collection of particles that includes an electron
gamma radiation
a kind of radioactivity involving the emission of energetic electromagnetic radiation from the nucleus of an atom, with no change to the number of protons or neutrons in the atom
half-life
the rate of radioactive decay measured by the time it takes for half of a collection of isotopes to decay into another element
radiometric dating
a technique based on the half-life of carbon-14 that is used to determine the age of materials
fission
a reaction that produces energy when heavy radioactive nuclei split apart into fragments that together have less mass than the original isotope
fusion
a process in which two atomic nuclei come together to form a third, large nucleus.
critical mass
the minimum number of uranium-25 atoms needed to sustain a nuclear chain reaction to the point where large amounts of energy can be released
nuclear reactor
a device that controls fission reactions to produce energy when heavy radioactive nuclei split apart
high-energy/ elementary-particle physics
the study of particles that comprise the basic building blocks of the universe; for example, the particles that make up the nucleus and particles such as electrons
cosmic rays
particles (mostly protons) that rain down continuously on Earth’s atmosphere after being emitted by stars in our galaxy and in others
particle accelerator
a machine, such as a synchrotron, that produces particles at near light speeds for use in the study of the fundamental structure of matter
synchroton
a particle accelerator in which magnetic fields are increased as particles become more energetic, keeping them moving on the same track
large Hadron collider
the world’s highest energy particle accelerator, located in Geneva, Switzerland
leptons
a particle (such as the electron, muon, or neutrino) that participates in the weak and electromagnetic, but not the strong interaction
hadrons
particles, including the proton and neutron, that are made from quarks and are subject to the strong force
antimatter
particles that have the same mass as their matter twins, but with an opposite charge, magnetic characteristics, and other properties.
quarks
the truly fundamental building blocks of the hadrons. particles that have fractional electrical charge and cannot exist alone in nature.
unified field theory
the general name for any theory in which fundamental forces are seen as different aspects of the same force
string theories
theories that unify gravity with other forces and visualize matter as made up of vibrating string
astronomy
the study of objects in the heavens
star
objects that form from giant clouds of interstellar dust and generate energy by nuclear fusion reactions
telescope
a device that focuses and concentrates radiation from distant objects
solar wind
a stream of charged particles– mainly ions of hydrogen and electrons– emitted constantly by the Sun into the space around it
light-year
the distance light travels in one year- 10 trillion kilometers
neutron star
a very dense, very small star, usually with a high rate of rotation and a strong magnetic field; the remains of a supernova, held up by the degeneracy pressure of neutrons
blackhole
formed at the death of a very large star, and object so dense, with a mass so concentrated, that nothing– even light– can escape from its surface
main-sequence star
a star that derives energy from the fusion reactions of hydrogen burning; found on the Hertzsprung-Russel (H-R) diagram within a band-like pattern
red giant
an extremely large star that emits a lot of energy but whose surface is very cool and therefore appears somewhat reddish in the sky; found in the upper right-hand corner of the H-R diagram
white dwarf
a star that has a very low emission of energy but very high surface temperature; plots on the lower left-hand corner of the H-R diagram
nebulae
dust and gas clouds, common throughout the milky way, rich in hydrogen and helium
supernova
a stupendous explosion of a star, which increases its brightness hundreds of millions of times in a few days; results from the implosion of the core of a massive star at the end of its life
pulsar
a neutron star giving off EM radiation
milky way
a collection of hundreds of billions of stars that forms the galaxy of which the sun is a part
WIMPs
weakly interacting massive particles- hypothetical particles that are candidates for dark matter
dark matter
material that exists in forms that do not interact with EM radiation and that may constitute 90% of the matter of the universe
dark energy
a mysterious substance that is causing the acceleration of the expansion of the universe
Hubble’s law
the law relating the distance to a galaxy, d, and the rate at which it recedes from the Earth, V, as measured by the redshift: V=Hd, where H is the Hubble constant
big bang theory
the idea that the universe began at a specific point in time and had been cooling and expanding ever since
cosmic microwave background radiation
microwave radiation falling to Earth from all directions. this radiation is evidence of the big bang theory
solar system
sun, planets, their moons, and all other objects gravitationally bound to the sun
terrestrial planets
planets located in the inner solar system that are small, high-density, and rocky
differentiation
process by which heavy dense material, like iron and nickel, sunk to the core while lighter, less dense material came to the top creating our layered structure of planet
core
geology- densest, innermost part of earth
astronomy- center of stars where hydrogen burning is confined
crust
earths outermost, solid layer
kuiper belt
a region close to our solar system that contains comets that orbit the sun
mantle
outside the core and contains most of earth’s mass
asteroid belt
a collection of asteroids located in a circular orbit between mars and jupiter; debris that never became a planet
pluto
used to be ninth planet but is now considered the first plutoid discovered
earthquake
disturbance caused when stressed rock on Earth’s surface suddenly snaps, converting potential into kinetic energy
plutoid
planet-like bodies in the Kuiper belt
convergent plate boundary
where plates come together
hot spot
a type of volcanism associated with plate tectonics- large isolated chimney-like columns of hot rock rising to earths surface
meteor
a piece of interplanetary debris that hits earth’s atmosphere that we see as a shooting star
meteorite
fragment of meteor that hits earth
volcano
places where subsurface molten rock breaks through to the earths surface to form dramatic short term changes in the landscape
plate tectonics
theory that explains how tectonic plates are moved across earths surface by mantle convection
tectonic plates
sheets of moving rock in various sizes forming earths surface
mantle convection
a force deep within earth, powered by internal heat energy, that moves tectonic plates
transform plate boundary
where plates scrape past one another with no new material being produced
subduction zone
region of earths deep interior where plates converge and old crust returns to the mantle
seismology
the study and measurement of vibrations within the earths interior dedicated to deducing earths inner structure
