Physical Science 1

Physical Science 1

  • Physical Science Branches: Physics, Earth, Chemistry, and Astronomy.
  • Big bang theory

- explains how the universe began

- this is an expansion

  • Atom - is the building block of matter
  • Molecules - atoms combine to form
  • ATOMIC THEORY
    • States of Matter - Solid, Liquid, Gas
    • History:
      • Thales - “water constituted all matter.”
      • Empedocles - “Matter is made up of four elements.” (earth, air, fire, water)
      • Leucippus - “A material will reach a point that it can never be divided.”
      • Democritus - “Materials are made up of tiny, indivisible and indestructible particles called atom.”
      • Newlands - increasing order of atomic masses.
      • Mendeleev - Periods and Columns
          • The Evolution of the Models of Atom:

Atomism

  • 5th Century BC
  • Proposed by Democritus.
  • All matter is made up of tiny, indivisible particles called atoms.
  • It is derived from the word “atomos,”
      • Solid Sphere
  • 1803
  • Proposed by John Dalton
  • Atoms are tiny, indestructible spheres with no internal structure.
      • Plum Pudding Model
  • 1904
  • Proposed by J.J Thomson
  • Atom have a + charge sphere and negative e- scattered.
  • Also referred as the raisin bread model.
  • Cathode Ray Experiment
  • Nuclear Model
  • 1911
  • Proposed by Rutherford
  • Most of the mass comes from the nucleus.
  • E- are orbiting around it.
  • It became the basis of the atomic structure today.
  • Schrodingers Model

-1926

- describes the quantum mechanical behavior of electrons in atoms using wave functions

  • Nucleosynthesis
    • Evidences of the BIG BANG
  • Cosmic Expansion
  • CMB (Cosmic Microwave Background)
  • Nucleosynthesis
  • 3 Types of Nucleosynthesis
    • Big Bang - refers to the formation of light elements like hydrogen, helium, and a small amount of lithium in the early universe, occurring within the first few minutes after the Big Bang.
    • Stellar - In the cores of stars, nuclear fusion processes generate energy and create heavier elements from lighter ones. Main sequence stars like our Sun fuse hydrogen into helium through thermonuclear reactions
    • Supernova - is a powerful stellar explosion that occurs at the end of a star's life, marking its dramatic collapse and subsequent release of immense energy.
    • Big Bang Nucleosynthesis
  • Factors that led to it:
  • Temperature & energy.
  • As a result, quarks & gluons formed the p+ and n0.
  • The creation of a new element from p+ and n0.
  • NUCLEAR FUSION.
  • It led to the creation of light elements. Ex: H to He

✭ Isotopes

  • Isotopes are family of element. It all has:
  • Same # of p+, Different # of n0
  • Same atomic #, Different mass #
  • Isotopes may be stable or unstable.

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✫ Stellar Nucleosynthesis

  • Formation of elements from the stars’ interior.
  • Factors that led to it:
  • Density & Temperature
  • 1. Proton-Proton Chain: Fusion of 4 H nuclei to form He
  • 2. CNO Reaction: Conversion of H to He by using Carbon.

✯ Proton-Proton Chain Reaction

✬ CNO Cycle (Carbon, Nitrogen, Oxygen)

✮ Stellar Nucleosynthesis

  • 3. Tri-Alpha process:
  • 3 He combine to form Be.
  • 4. Alpha Ladder Process:
  • Adding He for every element to form new element.

✯ Triple Alpha Process

✯ Alpha Ladder Process

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