AST201H1 Lecture : matter, spectroscopy, doppler shift

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Stefan Mochnacki

Document Summary

1 au= 215 solar radii (radius of the sun) Atomic number= # of protons in nucleus (+ charged) Atomic mass number= # of protons + neutrons. Molecules= consist of 2 or more atoms (h2o, co2) Isotope= same # of protons but different # of neutrons. Phases of same material behave differently because of differences in chemical bonds. Phase changes ionization: stripping of electrons, changing atoms into plasma dissociation: breaking of molecules into atoms evaporation: breaking of flexible chemical bonds, changing liquid into solid melting: breaking of rigid chemical bonds, changing solid into liquid. Phases and pressure phase of a substance depends on both temperature and pressure often more than one phase is present. Electrons in atoms are restricted to particular energy levels. Atom consists of a nucleus (+) and electrons (-) in a cloud of orbits around it. Electrons gain energy by dropping into another electron level closer to the nucleus www. notesolution. com.