Nuclear Chemistry By Sean Burnette, Ryoto Furuya, Minho Oh, Kendall Mandrell, Vincent Carlo Caracappa, Joe He, Mark, Courtney Hebard, and Alejandra Romanos

Radioactivity 10.1 Key Concepts -What happens during nuclear decay? During nuclear decay, atoms of one element can change into atoms of a different element altogether. -What are three types of nuclear radiation? Common types of nuclear radiation include alpha particles, beta particles, and gamma rays. -How does nuclear radiation affect atoms? Nuclear radiation can ionize ions -What devices can detect nuclear radiation? Devices that are used to detect nuclear radiation include Geiger counters and film badges.

Nuclear Decay -Radioactivity is the process in which an unstable atomic nucleus emits charged particles and energy. Any atom containing an unstable nucleus is called a radioactive isotope, or radioisotope for short. Radioisotopes spontaneously When the composition of a radioisotope changes, the isotope is said to undergo Nuclear decay. Scientists can detect a radioactive substance by measuring the nuclear radiation It gives off . Nuclear radiation is charged particles and energy that are emitted from the nuclei of radioisotopes. 3 common types of nuclear radiation include alpha particles, beta particles, and gamma radiation.

Alpha Decay -An alpha particle is a positively charged particle made up of two protons and two neutrons (it has a +2 charge). Alpha decay, which refers to nuclear decay alpha particles, is an example of a nuclear reaction. -In alpha decay the product isotope has two fewer neutrons than the reactant isotope. In the equation above, the mass on the left equals the sum of the mass numbers on the right. In other words the equation is balanced. -Alpha particles are the least penetrating type of nuclear radiation. Most alpha particles travel no more than a few centimeters in air, and can be stopped by a sheet of paper or clothing

Beta Decay A beta particle is an electron emitted by an unstable nucleus. Because of its single negative charge, a beta particle is assigned an atomic number of -1 and a mass number of 0. During beta decay, a neutron decomposes into a proton and an electron. The proton and an electron. The proton stays trapped in the nucleus while the the electron is released. In beta decay, the product isotope has one proton more and one reactant fewer than the reactant isotope. The mass numbers of the isotopes are equal because the emitted beta particle has essentially no mass. Due to their smaller mass and faster speed, beta particles are more penetrating than alpha particles.

Gamma Decay -A gamma ray is a penetrating ray of energy emitted by an unstable nucleus. Gamma rays have no mass or charge. Gamma rays travel through space at the speed of light. -During gamma decay, the atomic number and mass number of the atom remain the same, but the energy in the nucleus decreases. Gamma decay often accompanies alpha or beta decay. -Gamma rays are much more penetrating than both alpha or beta particles

Effects of Nuclear radiation -What some may not know is that people are exposed to radiation constantly through background radiation or nuclear radiation that occurs naturally in an environment. -Radiation promotes growth in cancers Nuclear radiation can ionize atoms

Detecting Nuclear radiation Geiger Counter -ionizes atoms in a gas then ions produce electric current when which measure radiation Film Badges -Film badges are used to monitor exposure to nuclear radiation.

Rates of Nuclear Decay 10.2 Key Concepts How do nuclear decay rates differ from chemical reaction rates? Unlike chemical reaction rates, which vary with the conditions of a reaction, nuclear decay rates are constant. How do scientists determine the age of an object that contains carbon- 14 In radiocarbon dating , the age of an object is determined by comparing the object’s carbon 14 levels with carbon-14 levels in the atmosphere.

Vocab -Half life: The time required for one half of a sample of a radioisotope to decay. Radiocarbon dating can be used to find how old something is. This relates to nuclear decay for the more decayed the specimen is the older it is etc.

Artificial Transmutation 10.3 -Scientists can preform artificial transmutations by bombarding atomic nuclei with high-energy particles such as protons, neutrons, or alpha particles. Scientists can synthesize a transuranium element by transmutation of a lighter element.

Fission and Fusion10.4 Nuclear forces -The strong nuclear force is the attractive force that binds protons and neutrons together in the nucleus. Because the strong nuclear force does not depend on charge, it acts among protons, and neutrons. Over very short distances, the strong nuclear force is much greater than the electric forces among protons. The more protons in the nucleus, the more greater the electric force. Unstable nuclei happens when the strong nuclear force can no longer overcome the repulsive electric forces among the protons

Fission -Fission is splitting of an atomic nucleus into two smaller parts. In nuclear fission, tremendous amounts of energy can be produced from very small amounts of mass. Example, the nuclear energy released by the fission of 1 kilogram of uranium- 235 is equivalent to the chemical energy produced by burning more than 17,000 kg of coal. Converting mass into energy: when fission of uranium -235 is carried out, about .1 percent of the reactant is lost during the reaction. The lost mass is converted to energy. Chain reaction, neutrons released during the spitting of an initial nucleus trigger a series of nuclear fissions. Critical mass is the smallest possible mass of a fissionable material that can sustain a chain reaction.

Fusion -Fusion is a process in which the nuclei of two atoms combine to form a larger nucleus. As in fission, during fusion, a small fraction of the reactant mass is converted into energy. Matter within the sun and other stars exist as plasma. Plasma is a state of matter in which atoms have been stripped of their electrons. Fusion occurs at millions of degrees Celsius, plasma can exist at much lower temperature. Scientists estimate that more than 99 percent of matter in the universe is plasma. Scientist face two main problems in designing a fusion reactor. They need to achieve high temperature required to start the reaction, and they must contain the plasma.