Chapter 28 chem

beta radiation
formed by the decomposition of a neutron in an atom; the neutron decomposes into a proton remaining in the nucleus and a released electron; the released electron is called a beta particle; beta particles have less charge and less mass than an alpha particle

alpha radiation
formed by Helium nuclei that have been emitted by a radioactive source; emit two protons and two neutrons which compose a an alpha particle and have a double positive charge

gamma radiation
high energy electromagnetic radiation is given off by an isotope; produce gamma rays which have no mass and no electrical charge so it does not alter the atomic number or mass of an atom; often ommited with alpha or beta radiatoin by the nuclei of disentegrating atoms

conversion of an atom of one element to an atom of another element; occurs during radioactive decay; occurs when high energy particles bombard the nucleus of an atom, where high energy particles protons, neutrons, or alpha particles; occurs with any elements whose atomic number is 92 or above (called transmurium elements, none of which occur naturally)

nuclear fission
occurs when the nuclei of certain isotopes are bombarded with neutrons; the nucleus splits into smaller fragments; a fissionable atom is struck by a slow moving neutron and splits into two fragments of roughly the same size; more neutrons are also released by fission, causing a chain reaction; releases a lot of energy, especially in uncontrolled reactions where total energy release is almost instantaneous; in controlled fission reactions, energy can be produced more slowly

nuclear fusion
nuclei combine to produce a nucleus of greater mass; requires two beta particles in order to occur; occur only at very high termperatures (4×10^7 c and higher;

positron emission
protons converted to neutrons; occurs with lighter elements; emits a proton

electron capture
first energy electron captured by nucleus; occurs with heavier elements; the 0/-1e is a parent nuclide

difference between electron capture and beta emission
electron capture the 0/-1e is a parent nuclide and beta emission it is emitted; electron capture occurs when there are too many protons compared to neutrons and beta emission occurs when there are too many neutrons compared to protons

how can you tell when each reaction is bound to happen?
neutron to proton ratio; beta emission occurs when there are too many neutrons; electron capture, positron emission and alpha radiation occur when there are too many protons; nuclear fission occurs with nuclei of an atomic number 83 or greater and nuclear fusion occurrs with nuclei of an atomic number of 92 or more

particle penetration of the particles
alpha: low; beta positron and proton moderate; gamma very high; neutron high; low (can go through .05 mm body tissue and is stopped by paper and clothing); very high (can easily go through a body; stopped by lead and concrete but not completely; moderate(can go through 4mm body tissue and is stopped by metal foil)

applications of gamma rays in real life
x rays behave similarly

1/2 lives real life application
1/2 lives can be used to find the age of ancient artifacts; if half life is short it can be used in nuclear medicine because it will have no long term radiation danger to the patient

application of fission
uncontrolled fission reactions are used for atomic bombs; controlled fission reactions are used for producing energy via nuclear reactors

application of fusion
scientists are considering using a controlled version to produce energy because it would be inexpensive and the fuel would be readily available; however cannot get to high enough temperatures and it if the temp could be attained the matter would turn to plasma and that nothing can contain plasma yetq

ionization radiation
x rays and radiation omitted by radioisotopes that have enough energy to knock off electrons from the bombarded substance to produce ions

Ways of detecting radiation and why
because radiation cant be felt using the five senses; geiger counter (gas filled metal container sends a current to a speaker when radiation enters and ionizes gas, causing audible clicks); scintillation counter(specially coated phosphor surface, radiation strikes surface to produce light that is converted to recorded electronic pulses); film badge (layers of photographic film and black film in box, film checked at intervals to measure type and intensity of radiation based on the blackening of film)

uses of radiation
neutron activation analysis: detects trace amounts of elements in samples ; tracer radioisotopes used to study chemical reactions in molecular structures by adding radioistopes to reactants and using the utake compared to the original isotope amount to study reactions, can also be used to determine effect on plants and animals, uptake of iodine 131 measured to detect thyroid problems and radiation therapy used to treat cancer

nuclear reactions
the nuclei of unstable isotopes, radioisotopes, gain stability by undergoing changes; cannot be sped up slowed down or turned off`

the process of emitting particles and energy form the nucleus of an unstable isotope (radioisotope) to become stable

radioactive decay
the spontaneous disintegration of a nucleus into a slightly lighter nucleus, accompanied by radation; analagous to decomposition in chemical changes

the particles or energy emitted from the nucleus

what are some differences between nuclear reactions and chemical reactions
in nuclear reactions elements may be converted from one to another and in chemical reactions no new electrons can be produced. in the nuclear reactions particles within the nucleus(electrons inside nucleus) are involved and in chemical reaction sonly electrons participate / reactions occurs outside nucleus; in nuclear reactions tremendous amounts of energy are released or absorbed and in chemical reactions relatively small amounts of energy are released or absorbed; in nuclear reactions the rate fo reaction is not influenced by external factors (the environment has nothing to do with how fast a reaction occurs) and in chemical reactions the rate of reaction depends on factors such as concentration, temperature, catalyst, and pressure (the environment)