HSC Chemistry Assessment task 1 Nuclear Chemistry Research report 1. Distinguish between stable and radioactive isotopes and describe the conditions which a nucleus is unstable. To understand if an element is stable we first must understand what stability is. The stability of the nucleus is directly related to the strength of the forces that hold the nuclear particles together. These protons and neutrons of the nucleus are called nucleons.
Visible light rays and x-rays work in a similar manner, both being wavelike forms of electromagnetic energy carried by particles called photons. “The photon concept was introduced by Albert Einstein in order to explain physical phenomena that could not be understood based on the wave properties of light” (Bensaada, Ouellette, 2011, pg 32). The only difference between both is the energy levels of these photons, which is expressed as the wavelength of the rays. Visible light rays and X-Rays are produced by the movement of the electrons in the atom. Another form of more sophisticated X-rays are CT Scans, computer tomography also known as Cat Scans.
In 1883 Hertz became a lecturer in theoretical physics at the University of Kiel. Two years later he was appointed professor of physics at Karlsruhe Polytechnic. In the 1880s physicists were trying to obtain experimental evidence of electromagnetic waves. Their existence had been predicted in 1873 by the mathematical equations of James Clerk Maxwell, a British scientist. In 1887 Hertz tested Maxwell's hypothesis.
More than a century later, Einstein, came up with the theory of relativity. It states that nothing can travel faster than the speed of light, therefore, no matter can escape it. (O.N.L. 47-56) Karl Schwarzschild, in 1917 used Einstein theory to calculate that if a star of a curtain mass was to shrink pasted the critical point it would become a Black Hole. The theory is named in his honor, the Schwarzschild radius.
George Simon Ohm (1787-1854), a German physicist, in 1826 experimentally determined the most basic law relating voltage and current for a resistor. Ohm’s work was initially denied by critics. Born of humble beginnings in Erlangen, Bavaria, Ohm threw himself into electrical research. His efforts resulted in his famous law. He was awarded the Copley Medal in 1841 by the Royal Society of London.
From Hydrogen to DNA Task One – Thinking Questions The movement and mixing of particles is known as diffusion. Explain why diffusion occurs in liquids and gases but not solids. Diffusion occurs in liquids and gases because molecules in a solid don not have the ability to move around. Aluminium has a melting point of 660 degrees Celsius what is its state at a) 1000 degrees Celsius - At 1000 degrees Celsius the state of Aluminium would be a liquid b) 500 degrees Celsius – At 500 degrees Celsius the state of Aluminium would be a solid. How are Neutrons different between Protons?
Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle. 6. A pulsar does not pulse, it emits beams of radiation that sweep around the sky as the neutron star rotates, and astronomers detect pulses when they sweep over the Earth. 11. Sometimes in binary systems, mass flows into a hot accretion disk around the neutron star and causes the emission of x rays.
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.
Subatomic Particles and the periodic table 1. The three particles and their properties An atom has no overall charge. The protons (positively charged) and neutrons (no charge) make up the nucleus of an atom, and this is surrounded by negatively charged electrons. There are as many protons as electrons, so they balance each other out, creating a neutral relative charge on the atom. Neutrons, Protons and electrons are all sub-atomic particles.
Chapter Assessment Answer Key Chemistry: Matter and Change T167 4 CHAPTER ASSESSMENT Date alpha radiation Dalton’s atomic theory radiation radioactivity Chapter Assessment particles involved in a reaction. Chemistry: Matter and Change • Chapter 4 nucleus. A nuclear equation shows the atomic number and mass number of the 19 Both concern changes in atoms. A nuclear reaction involves a change in an atom’s 15. nuclear reaction, nuclear equation atom. in the nucleus of a given atom.