Finals Physci

• Matter

  Anything which has mass, occupies space and can be perceived by our senses. "Matter is everything".
• Volume

  Space that is occupied
• Mass

  Amount of matter (consistent)
• Weight


  Connected to gravity
• Gravity

  Weakest force but it governs everything
• Big Bang Theory

  • It is the most prevailing cosmological theory on the origin of the universe
  • It postulates that 13.7 billion years ago, the universe experienced a sudden inflation (not an explosion) from a singularity to its present size and much cooler state
• Edwin Hubble


  He proposed that galaxies are moving from one another and this statement became evidence of an expanding universe
• George Lemaitre


  • First proponent to attempt an explanation of Big Bang Theory based on the notion of the "primeval atom"
  • The primeval atom is termed today as the singularity
  • The singularity is the initial condition of the universe wherein it is an infinitely hot and infinitely dense state that has undergone expansion up until this time
• George Gamow


  Formulated the Big Bang Theory known today, which is backed up with evidence. It holds the premise that the universe came into being from a gigantic inflation of the primeval atom or the singularity
• Structure and composition of the cosmos

  • Baryonic matter (5%)
  • Dark matter (27%)
  • Dark energy (68%)
• Universal redshift


  • Infers that the galaxies are moving away from one other which supports the expansion of the universe
  • Observation through spectroscope; indicates color (doppler effect of light)
• Doppler effect


  • A phenomenon associated with waves, sound waves and light waves included
  • If sound is near, pitch and sound increase
  • If sound is far, pitch and sound decrease
  • Sound and light travel through waves; these have frequency, energy, and wavelength. (where energy and frequency are proportional)
• EM spectrum


  • Visible light (ROYGBIV)
  • Violet has the shortest wavelength
  • Red has the longest wavelength
  • Hubble observed the light appeared displaced toward the red end of the spectrum; this proves that the universe is expanding
• Cosmic microwave background radiation

  • The first "afterglow" of the hot, early universe
  • Heat remnant of the Big Bang Theory; Heat and Radiation are distributed everywhere
  • The cosmic microwave background radiation is the oldest light you can see
  • Up until this time, cosmic microwave background radiation has cooled down since the Big bang and can be detected throughout the universe
• Abundance of light elements

  • It is not until 3 minutes after the Big Bang when subatomic particles proton and neutron join together to form the nuclei of the first elements in the universe which is Hydrogen
  • Series of thermonuclear reactions take place for the first Hydrogen nuclei to combine and form the nuclei of the next light element which is Helium
• Nucleosynthesis


  • Formation of atomic nucleus
  • As the Universe cools, protons and neutrons can fuse to form heavier atomic nuclei
  • Nucleus have protons and neutrons; change of atom = change of mass
  • Atomic number (Subscript): number of protons
  • Atomic mass (Superscript): components
• Stages of nucleosynthesis


  • Primordial
  • Stellar
  • Supernova
• Primordial nucleosynthesis


  • The building up of complex atoms through the formation of deuterium nuclei or deuterons: n + p -> d + y
  • The breaking up of a deuteron nuclei apart into its complex components: d + y -> n + p
  • All of the free neutrons in the universe were rapidly bound in the deuterium nuclei, and from then on other light nuclei formed
• Stellar nucleosynthesis


  • The production of nuclei heavier than Hydrogen in stars
  • Matter that was uniformly distributed clumped together and began to form proto-galaxies
  • Collapse of internal lumps took place under gravitational force
• How stars are formed

  1. About a hundred thousand years later, as the universe undergoes continuous expansion, matter clumped together and formed lumps called proto-galaxies

  2. Gravitational force played a very vital role in the formation of the universe, all the celestial bodies in here, the galaxies and the stars and planets within these galaxies

  3. Gravity governs everything in the universe even though it is the weakest of all the four forces in nature and according to Newton's universal Law of Gravitation, it causes two bodies with mass to be attracted to each other
• Why don't the sun collapse?


  • Gravity pushing the material inward counterbalances the outward pressure of gas created by energy in nuclear fusion results in stabilities within the star
  • This equilibrium between gravity and pressure prevents the star from collapsing or blowing apart
  • 4He + 4He + 4He -> 12C + y : Stars evolve so that they have onion-like shells of successively heavier elements where different thermonuclear reactions take place
• Fate of stars


  Depending on the mass of stars, fusion will continue until the star produces heavier elements in its core. The crucial difference between them is not really the size but the heat or temperature the star can generate to provide continuous nuclear fusion. In massive stars, an onion skin was produced because of consecutive nuclear fusion with the elements becoming heavier as you go to the core
• Supernova nucleosynthesis


  • Having stellar nuclear burning stops at Iron, gravitational forces take over and the core collapses quickly and catastrophically
  • This cataclysmic explosion is known as a supernova
  • The massive stars that end up as supernovas manufacture elements heavier than Iron which are Gold, Silver, Mercury and they are distributed throughout space and can become a part of a new star, planet, and galaxy
• Democritus and Leucippus


  • Proposed the concept of atomism. Their ideas are more philosophical than scientific
  • Their idea about matter is that even if a material is broken down into pieces, each piece will retain the properties of the original piece where it came from
• Democritus

  He coined the term atomos, which means indivisible
• Ancient philosophers' ideas about matter

  • Thales (matter is made up of water)
  • Anaximenes (air as the basic element)
  • Heraclitus (matter are made up of fire)
  • Empedocles (everything is made up of four eternal and unchanging kinds of matter: fire, air, water and earth)
• Alchemy

  An early philosophical and spiritual field of study that combined chemistry and metal work. Its primary aim was to transform metal into gold
• Robert Boyle

  • First challenged the Aristotelian and the alchemists' concept of elements
  • He viewed that a substance is an element if it cannot be further broken down into simpler substances
  • He opposed the belief of alchemists that matter is made up of the three essences (salt, sulfur, mercury) because he argued that these substances cannot constitute matter because these three essences cannot be extracted from all matter
• Law of conservation of mass

  • Proposed by Antoine Lavoisier, the Father of Modern Chemistry: Total mass before a reaction = Total mass after a reaction
  • The mass of the matter undergoing a chemical change is conserved
  • Matter can neither be created nor destroyed by physical or chemical means
• Antoine Lavoisier

  Considered as the Father of Modern Chemistry and proposed one of the laws that made a breakthrough in the field of Chemistry
• Law of definite proportions

  • Proposed by Joseph Proust
  • All samples have the same proportions by mass of its constituents
  • Elemental composition of a pure compound is always the same regardless of where it comes from
• Joseph Proust

  Spent years studying compounds
• Law of multiple proportions

  Proposed by John Dalton
• Dalton's atomic theory


  • All matter is composed of atoms that are indestructible
  • The atoms of a given element are identical
  • Atoms of different elements combine with each other in a definite ratio of small whole numbers to form a compound
  • In chemical reactions, atoms are not destroyed. They only combine with each other or are separated from one another
• Plum-pudding model


  Atoms are pictured as homogenous spheres of positive charge which spread evenly throughout the atom, and the small negative particles which are the electrons are embedded within. Distinct negative charges are floating within a sea of positive charge
• Nuclear model


  • The atom has an empty space that has a dense positively charged center
  • Ernest Rutherford made observations proving that the atomic mass is concentrated at the center or nucleus of the atom where the proton is located
  • The foundation of Rutherford's atomic model was based on the gold-foil experiment he and his colleagues conducted
• Planetary model


  Proposed by Niels Bohr: The electrons move in orbits around the nucleus at set energy levels or quanta
• Quantum model


  Proposed by Erwin Schrodinger: Instead of orbits, there is an area with high probability of finding the electron and it is called the electron cloud
• Proton


  Positively charged particle located in the nucleus
• Neutron


  Zero charged particle and located in the nucleus