Astronomy 10 Chapter 11 1. Both used to be normal stars but the white dwarf ran out of hydrogen, they are both subjected to gravitational theories. A Neutron star is a fluid of neutrons, as hot at its surface as the inside of the sun and has a greater magnetic field. 3. Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle.
INTRODUCTION TO NUCLEAR REACTION: The main features of nuclear reactions include radioactive decay, nuclear fission and nuclear fusion. Radioactive decay: Energy is released in a radioactive decay in the form of the kinetic energy of the particle emitted (α and β), the kinetic energy of the daughter nucleus and the energy of the gamma-ray photon that may accompany the decay. The energy involved may be calculated by finding the mass defect of the reaction. The energy released is the energy equivalent of the mass defect of the reaction. Nuclear fission: Nuclear fission is the process in which a large nucleus breaks into two smaller nuclei that are almost equal in mass.
Describe two ways in which gravity has a part in the life-cycle of a star- Gravity pulls the dust and gas in the nubula together, and compresses them so much that the inside becomes hot enough for fusion reactions to start. Gravity also pulls the remains of a red giant together after fusion reactions have stops. This forms a white dwarf. Theories about the universe- 1. What does red shift tell s about distant galaxies?
David Kemp OCR Chemistry A Unit 1: F321 Atomic Structure (a) describe protons, neutrons and electrons in terms of relative charge and relative mass; Proton +1 1 Neutron 0 1 Electron -1 1/2000 Relative Charge Relative Mass (b) describe the distribution of mass and charge Within an atom; Positively charged Nucleus containing most of the mass, surrounded by atomic shells with orbiting electrons of negative charge and negligible mass. (c) describe the contribution of protons and neutrons to the nucleus of an atom, in terms of atomic (proton) number and mass (nucleon) number. The atomic number of the nucleus, also the proton number, shows the number of protons in the nucleus. It also defines the element. The number of neutrons added to the number of protons is the nucleon number or mass number.
This causes the excitation of two electrons, and they move to a higher energy level. These high-energy electrons move along electron transport chains in a series of redox reactions, releasing energy which activates the enzyme ATPase required in the production of ATP. Reduced NADP (NADPH) is also formed during the light-dependent reaction. The products ATP and reduced NADP from the light-dependent reaction are then used in the light-independent stage of photosynthesis (aka the Calvin cycle). Both ATP and NADPH are responsible for the reduction of glycerate-3-phosphate into triose phosphate, which is converted into many useful organic compounds like carbohydrates, mainly glucose.
Charging a Two-Sphere System Using a Positively Charged Object The above examples show how a negatively charged balloon is used to polarize a two-sphere system and ultimately charge the spheres by induction. But what would happen to sphere A and sphere B if a positively charged object was used to first polarize the two-sphere system? How would the outcome be different and how would the electron movement be altered? Consider the graphic below in which a positively charged balloon is brought near Sphere A. The presence of the positive charge induces a mass migration of electrons from sphere B towards (and into) sphere A.
An optimised imaging modality would result from a combination of these properties. One such emerging technique that achieves this is Cherenkov Luminescence Imaging (CLI). CLI harnesses Cherenkov radiation to image radionuclides using OI instruments2. Cherenkov radiation is a well known phenomenon that arises when charged particles, such as β- or β+ travel through an optically transparent material with a velocity that exceeds the speed of light in the material. As the particle travels through the medium it loses kinetic energy by polarizing the electrons of the given material.
Static electricity is produced from a process known as triboelectrification. To show how much static electricity an object has, it is determined by its position on the triboelectric series. Its position on this scale is determined by how tight the atom is holding the electrons. An atom is more positive in the triboelectric series if a material is more apt to give up electrons when in contact with another material. If a material is more apt to "capture" electrons when in contact with another material, it is more
This whole process is called a nuclear chain reaction. The reactor core generates heat as the kinetic energy is converted to thermal energy. Gamma rays are produced during fission and absorbed by the reactor, where thermal energy is converted to heat. Heat produced by the radioactive decay of fission production remains in the reactor, sometime even if it shut down.
Electromagnetism Everything is made out of atoms. Atoms consist of a nucleus (containing neutrons and protons) and a cloud of electrons surrounding the nucleus. Protons are positively charged and electrons are negatively charged. If an object has more protons than neutrons, then it is negatively charged. If an object has more electrons than protons, then it is positively charged.