Please help me this simple question Please answer questions

Please help me this simple question. Please answer questions 1 and 2.

5.7 Questions 1. What is a neutrino? What scientific observations led to its prediction? 2. Studying neutrinos helped to explain how our Sun works but led to changes in theories of particle physics. How is this process consistent with the scientific process? How can details about a theory be adjusted without undermining other discoveries made through the theory\'s predictions 3. Explain how the theory of neutrino oscillations helps to explain the missing electron neutrinos from the Sun. 4. Building large detectors underground can have an impact on the environment around the detector site. Do you think the knowledge we gain from studying neutrinos is worth the environmental impact? Explain your reasoning. ICI

Solution

Neutrinos are one of the fundamental particleswhich make up the universe. They are also one of the least understood.

Neutrinos are similar to the more familiar electron, with one crucial difference: neutrinos do not carry electric charge. Because neutrinos are electrically neutral, they are not affected by the electromagnetic forces which act on electrons. Neutrinos are affected only by a \"weak\" sub-atomic force of much shorter range than electromagnetism, and are therefore able to pass through great distances in matter without being affected by it. If neutrinos have mass, they also interact gravitationally with other massive particles, but gravity is by far the weakest of thefour known forces.

Three types of neutrinos are known; there is strong evidence that no additional neutrinos exist, unless their properties are unexpectedly very different from the known types. Each type or \"flavor\" of neutrino is related to a charged particle (which gives the corresponding neutrino its name). Hence, the \"electron neutrino\" is associated with the electron, and two other neutrinos are associated with heavier versions of the electron called the muon and the tau (elementary particles are frequently labelled with Greek letters, to confuse the layman). The table below lists the known types of neutrinos (and their electrically charged partners).

A Brief History of the Neutrino

Neutrino		ne		nm		nt
Charged Partner		electron (e)		muon (m)		tau (t)