PHYSCI 3Q

• singularity - small, dense, hot ball that expanded
• the universe expanded, not exploded
• inflation - expansion, 10^43 sec, the universe grew rapidly as particles called quarks formed
• formation of matter and anti-matter = quarks became hot as the universe was a sizzling primordial soup
• annihilation = cancellation of matter and anti-matter wherein particles were unstable that's why they don't last long
• big bang nucleosynthesis = their mobility slowed down and particles clumped down and formation of nucleus of atom began.
• hydrogen was the first element to form during expansion
• recombination = hydrogen was the first element in this sequence to form with 1 proton and no neutron
• in 3 minutes, hydrogen was formed
• dark ages = 300,000 years with 10,000 degrees celsius; hydrogen wasn't enough to emit light
• formation of cosmic bodies = occured 1 billion years ago in -200 degrees celsius; the first star was formed and universe was still expanding
• nucleo means nuleus
• nuclear fusion - nucleus combines with another nucleus to form larger nuclei
• nuclear fission - nucleus splits into smaller nuclei, splitting because of instability
• iron is the last element formed inside a star (nuclear fusion)
• supernova = explosion of star
• democritus described that all objects in universe are made by an indestructible and indivisible particle called atomos
• atom or atomos are the basic unit of matter
• john dalton tried to divide an atom but was inefficient
• john dalton made the solid sphere model where compounds around us are made of different atoms
• dalton's atomic theory states that matter is composed of tiny particles called atoms, which cannot be created nor destroyed, they can only change form
• joseph john thomson discovered negatively charged atoms, called electrons as he states that atoms have subparticles
• j.j. thomson presented the plum-pudding model of an atom
• ernest rutherford discovered positively charged atoms, called protons, using a gold foil experiment
• ernest rutherford presented nuclear model where protons are concentrated in the center with electrons surrounding it
• niels bohr said that electrons were not in constant motion / clumps of electrons
• niels bohr presented the planetary model of an atom
• erwin schrondinger supported bohr's idea that electrons are not fixed, hence you can only predict where it could be
• erwin schrondinger presented a formula that finds the probability of where the electrons could be
• cation = positive charged neutrons
• anion = negatively charged neutrons
• james chadwick discovered neutral charged atoms called neutrons
• neutron is found inside the nucleus
• the quantum theory explains the mathematical description of the wave properties of electrons and other small particles
• electrons are placed in regions called orbitals
• the quantum theory suggests the probability of finding an electron at a given place around the nucleus
• quantum numbers describe the orbitals in which electrons can be found
• principal (n) - size
• angular (l) - shape
• magnetic (m1) - orientation