Electron paramagnetic resonance

1. What is the forbidden gap in semiconductors? One electron volt (eV) 2. At absolute zero temperature, semiconductor behaves as Insulator 3. Define electrical conductivity. Electrical conductivity is the ability to conduct an electric current. 4. What are the two types of charge carriers in semiconductors? Electrons and holes are the two types of charge carriers in semiconductor. 5. Define charge carrier. Charge carrier is a particle, which carries electric charge or electric current from one…

electricity because it contains free electrons. Copper has one free electron per atom. The free electron concentration in copper is 8.5 x 1028 per m3. The electrons start flowing as soon as the switch is closed. But the electrons themselves travel much more slowly. So how does the current come on everywhere as soon as the switch is closed? It is because the free electrons are already spread throughout the wire. As soon as the switch is closed, there is a force on all electrons (i.e. electric…

melting point of -100.98 degrees Celsius and a boing point of -34.6 degrees Celsius. However, at room temperature it is a gas. Chlorine contains 17 protons and 17 electrons and also contains 18 neutrons. The density of the chemical element Chlorine is 3.214 c/cm3. Like every member of the halogen group, chlorine has a tendency to gain one electron and become a chloride ion. Chlorine…

form an atom are protons, neutrons, and electrons. Electrons are the smallest of the three particles that make up atoms. Electrons are found in shells or orbitals that surround the nucleus of an atom. Protons and neutrons are found in the nucleus. They group together in the center of the atom. Protons has mass (g) of1.673 x 10-24, Mass (amu) is 1 and location is nucleus, Neutrons has mass (g) of 1.675 x 10-24, mass (amu) is 1 and location is nucleus, and electrons has mass (g) of 9.109 x 10-28,…

1 on the periodic table. Hydrogen has an atomic mass of 1 and an atomic number of 1. Hydrogen has 1 VALENCE electron and 1 neutron. It has 1 ring, because it’s in period 1. Hydrogens state of matter is gas. Lithium is a Alkali Earth Metal on the Periodic Table. Lithium's state or matter is solid. Lithium has a atomic number of 3 and an atomic mass of 7 when rounded. It has 1 valence electron around its nucleus and 4 neutrons in the nucleus. Lithium has 2 rings because of its period. Beryllium is…

Atomic mass: the mass of an atom of a chemical element expressed in atomic mass units; approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes Molar mass: a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance Mole: the amount of a substance contained in 6.02 x 10²³ particles of that substance…

Topic 1: Chemical bonding 1.True or False: An Ion is when an atom gains or loses an electron. 2.What is a Cation? An ion with a (+) charge. 3.True or False: An Anion does not have a (-) charge. 4.What type of bonding transfers electrons? Ionic bonding 5.What are all the types of chemical bonds? Ionic, Covalent, and Metallic bonding. 6.What do you call an element that has different forms . Isotopes 7.Which type of bonding is the “strongest”? Ionic bonding 8.True or False: Ionic bonds are formed…

ions and electrons, the positive ions are attracted to the outside of the tube. The electrons are attracted to a metal wire running down the inside of the tube maintained at a high positive voltage. Many electrons travel down the wire making a burst of current in a circuit connected to it. The electrons make a meter needle deflect and you can hear a click every time radioactive…

The garnet ferrites have the general formula RFe5O12, where R is one of the rare earth metal ions (Y, Gd, Dy, Sm, Eu, Ho, Er, Tm, Tb and Lu). The first trail for synthesis of garnet Yttrium ferrite (Y3Fe5O12) was done by Bertaut and Forret in 1956 [39], this trial was followed by another one in 1957 when Geller and Gilleo prepared and investigated Gd3Fe5O12 [40]. The garnet ferrites have complex crystal structure with cubic shape. The cubic unit cell of garnet ferrites R3Fe5O12 contains 8…

The Physics of PET Scans All elements are composed of atoms, which are composed of small particles called protons, neutrons, and electrons. The nucleus of an atom is made of a tightly packed collection of protons and neutrons. You would think that with positively charged protons being packed so closely together the nucleus would fall apart, however this is not the case. There is an attractive force called the “nuclear force” which is able to overcome the repulsive force of the adjacent…