CHE 141 1st Edition Lecture 35Outline- Electrolysis: Driving Nonspontaneous Reactions with Electricity- Radioactivity- Types of Radioactive: a Decay - Types of Radioactivity: B Decay- Types of Radioactivity: y Emission- A Side Note on Antimatter- Types of Radioactivity: Electron Capture- Belt of StabilityElectrolysis: Driving Nonspontaneous Reactions with Electricity- Voltaic/galvanic cello Spontaneous redox reactiono Generates electrical energyo Electrons flow from anode to cathode- Electrolytic cello Nonspontaneous redox reactiono Driven by external electrical currentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Anode connected to positive terminal of power sourceo Cathode connected to negative terminal of power sourceo Electrons drawn away from anode ad pumped to cathodeRadioactivity- Nucleon particle making up the atomic nucleus (protons and neutrons)- Nuclide an atomic species characterized by the specific constitution of its nucleus - The symbol for a particular nuclide of element X is: A/Z X- A=mass number, number of nucleons- Z=atomic number, proton number- Number of neutrons N=A-Z- Subatomic particle particles that are smaller than an atom- Two types of subatomic particles: composite and elementary- Composite=made up of other stuff protons and neutrons- Elementary=not composed of other particles quarks and leptons- The symbol for a subatomic particle x is written in the same way as the nuclide symbol except the subscript represents the charge on the particle z- Proton symbol: 1/1 p- Neutron symbol 1/0 n- Electron symbol: 0/-1 e- Radioactive decay is the spontaneous disintegration of unstable particles accompanied by the release of radiationTypes of Radioactive: a Decay - Alpha (a) Decay an unstable nucleus emits a particle composed of two protons and two neutrons- Alpha particle (a) symbol: 4/2He or a- When an element emits an alpha particle, the number of protons in its nucleus changes- Parents nuclide the original atom- Daughter nuclide the product of the decay- To balance a nuclear equation, the sum of the atomic numbers (Z) on both sides ofa nuclear equation must be equal, and the sum of the mass numbers (A) on both sides must also be equal- We can deduce the identity and symbol of the daughter nuclide in any alpha decayfrom the mass and atomic number of the parent nuclideTypes of Radioactivity: B Decay- Beta (B) Decay in an unstable nucleus, a neutron changes into a proton and emits and electron: 0/-1 e or B-- When an atom emits a beta particle, its atomic number increases by 1 because it now has an additional protonTypes of Radioactivity: y Emission- Gamma (y) Ray Emission unstable nucleus emits high energy (short wavelength) photon- Gamma Ray (y) symbol: 0/0y or y- A gamma ray is electromagnetic radiation so has no mass and no charge- Gamma ray emissions does not change the atomic or mass number of the elementA Side Note on Antimatter- Antimatter is particles that are the charge opposite of normal subatomic particles- Positron a particle with the mass of an electron, but with a positive charge- When matter and antimatter collide they instantly annihilate each other- In their mutual destruction, all of their mass is converted into energy according to E=mc^2- Electron positron annihilation releases energy in the form of gamma rays (y)- Positron symbol: 0/1 e or B+- Positron emission in an unstable nucleus, a proton changes into a neutron and emits a positron: 1/1p0/0 n +0/1 e- When an atom emits a positron, its atomic number decreases by 1 because it nw has one less protonTypes of Radioactivity: Electron Capture- Electron capture unstable nucleus assimilates an electron from an inner orbital of its electron cloud, converting a proton into a neutron- Unlike the other forms of radiation, electron capture involves a particle being absorbed by rather than emitted from an unstable nucleus- Electron capture has the same net effect as positron emissionBelt of Stability- Stable nuclides form belt stability- Nuclides outside the belt of stability are radionuclides, unstable nuclides that undergo radioactive decay- The mode of radioactive decay depends on whether the radionuclide is above or below the belt of
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