Chapter 3- The Structure of Matter

What is an atom?
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Atomic nuclei that have same atomic mass number but different atomic #'s are?isobarsAtoms that have the same number of neutrons but different #'s of protons are?isotonesAtoms that have the same atomic # and the same atomic mass number are?IsomersAtoms of various elements may combine to form structures called?moleculesA chemical compound is?Any quantity of one type of moleculeThe smallest particle of an element is a(n) _________; the smallest particles of a compound is a(n) ________________.atom; moleculeWhat is radioactivity?the spontaneous emission of particles & energy in order to become stable.Radioactive decay results in what?The emission of alpha particles, beta particles, & usually gamma rays.What is the radioactive half life of a radioisotope?the time required for a quantity of radioactivity to be reduced to 1/2 its original value.3.3 radioactive half lives=1 radioactive tenth lifeWhat is an alpha particle?a helium nucleus that contains two protons and 2 neutrons.What is a beta particle?an electron emitted from the nucleus of a radioactive atom.Where do gamma rays come from? Where do x-rays come from?Gamma rays come from the nucleus; X-rays come from the electron cloud.The term atom was first used by the _____________.GreeksThe chemical element is determined by the number of ________________ in the atom.protonsTwo identical atoms which exist at different energy states are called ______________.isomersThe first person to describe an element as being composed of identical atoms was _______________.John DaltonThe max # of electrons that can exist in an electron shell is calculated w/ the formula ________.2n^2A positively charged nucleus surrounded by negatively charged electrons in well-defined orbits is the __________ model of the atom.BohrThe smallest particle that has all properties of an element is a(n) ________.AtomThe atomic # of an element is symbolized by the letter __________.ZWhen atoms of various elements combine, they form ____________.MoleculesThe innermost electron shell is symbolized by the letter _________.KAn atom in a normal state has an electrical charge of ________.ZeroThe binding energies, or energy levels, of electrons are represented by their ___________.shellsRutherford's experiments in 1911 showed that the atom was composed of _______________.A nucleus with an electron cloudWhat are the fundamental particles of an atom?Proton, neutron, electronAluminum has an atomic number of 13. How many protons does it have?13When an atom has the same number of protons as another, but a different # of neutrons, it's called an ______________.isotopeA neutral atom has the same number of _____________ & electrons.protonsAn atom that loses or gains one or more electrons is a(n) _____________.IonThe periodic table of elements was developed by _________________ in the late 19th century.MendeleevThe shell # of an atom is called the _________________.principal quantum numberWhat was the theory made by the Greeks about atoms?All matter is composed of 4 elements (water, earth, air and fire), they are combined to make substancesWhat was Democritus' atomic theory?Everything is composed of atoms and atoms are indivisible.What was Dalton's atomic theory? When did this theory originate?Atoms were tiny hard spheres with no empty space. 1803What was Thomson's atomic theory? When did theory originate?Atoms were positive spheres with negative electrons embedded withing (he discovered the electron)- Plum pudding model (1897)What was Rutherford's atomic theory? When did it originate?Atoms were mostly empty space with a nucleus in the center. 1909What was Bohr's atomic theory? When did it originate?Electrons moved in a fixed orbit (represents the best way to picture the atom). 1913What is the newer model of the atom?Quantum Chromodynamics (details of atomic structure are more accurately described)What are quarks and gluons?Protons and neutrons are made of quarks and bound together by gluons; quarks and gluons are the fundamental particles that make up composite hadrons (proton and neutron)What is atomic #?# of protonsWhat is atomic mass number?Number of protons and neutronsWhat is the theory of Quantum Chromodynamics?the theory of the strong interaction between quarks and gluonsWhat is matter?Anything that has mass and takes up spaceAtoms are the __________________________.fundamental building blocks of matterWhat is in the nucleus of an atom?Protons and neutrons (nucleons)What is the maximum number of electrons that can exist in the O shell?50(Particulate Radiation) Alpha Particles are _____________________?harmless unless deposited internally (ex- inhaled)(Particulate Radiation) Beta Particles can _____________________ ?penetrate tissue and inflict serious damage if inhaled or ingested(Electromagnetic Radiation)(photons) Gamma rays come from where?come from the nucleus of a radioisotope (no way to completely shield from gamma radiation)Electromagnetic Radiation(photons)- Xrays come from where?the electron shell (ionization)Whats the order of penetrating power of radiation? From least to greatestAlpha, Beta, x-ray, GammaWhat is electron binding energy?The strength of attachment of an electron to the nucleusThe ___________ an electron is to the nucleus, the more _____________ it is bound.closer; tightly (ex.- k shell electrons have higher binding energies than l shell electrons, l shell have more than m shell and so forth)What are chemical symbols?abbreviations for an element (ex- Ca is calcium) (O is oxygen)What is the most important factor that affects nuclear stability?the number of neutronsWhat can happen when a nucleus contains too few or too many neutrons?The atom can disintegrate radioactively, bringing the number of neutrons and protons into a stable and proper ratio.What does radioactive decay result in?the emission of alpha particles, beta particles, and usually gamma raysRadioisotopes _________ into stable isotopes of different elements at a decreasing rate so that the quantity of radioactive material never quite reaches _____________.disintegrate; zeroWhat two categories can ionizing radiation be put into?particulate radiation and electromagnetic radiationThe types of radiation used in diagnostic ultrasonography and MRI are ___________________.nonionizing radiationAlpha and beta particles are both associated with?Radioactive decayAfter being emitted from a radioactive atom, the alpha particle travels with a _________________ through matter. Because of its great mass and charge, it easily transfers this ____________________ to _____________________ of other atoms.high velocity; kinetic energy; orbital electronsThe energy of an alpha particle is quickly lost or stays for a long time?quickly lostAlpha particles have a ________________ in matter.very short rangeA beta particle is?an electron emitted from the nucleus of a radioactive atomAfter being emitted from radioisotope, beta particles _____________________ air, ionizing several hundred ____________ per centimeter.traverse; atomsThe beta particle range is _______________ than that of the alpha particle.longerDepending on its energy, beta particles may traverse how many cm of air and how many cm of soft tissue?10-100 cm of air; 1-2 cm of soft tissueX-rays and gamma rays are often called?photonsWhat is the mass and charge of a photon?no mass and no chargeThe only difference between x-rays and gamma rays is their?originGamma rays are emmited from where?emitted from the nucleus of a radioisotope and are usually associated with alpha or beta emissionX-rays and gamma rays exist at?the speed of light or not at allAfter x-rays and gamma rays are emitted what is their ionization rate in air?~100 ion pairs/cm, about equal to that for beta particlesIn contrast to beta particles, x-rays and gamma rays have ________________________ in matter.unlimited rangePhoton radiation loses what with distance? But theoretically never reaches?loses intensity with distance; never reaches zeroParticulate radiation has a ______________ range in matter and that range depends on the _________________.finite; particle's energyWhat is centrifugal force?The force that causes an electron to travel straight and leave the atom.