mean - physical science

Subdecks (1)

Cards (114)

  • Stellar Nucleosynthesis
    The formation of elements in the center of a star
  • The formation of the universe began through the explosion of a primordial atom which happened approximately 13.7 billion years ago
  • Big Bang theory
    Theory introduced by Edwin Hubble describing the origin of the universe
  • In 1929, Hubble demonstrated that all celestial objects in the universe move away from each other
  • Big Bang Nucleosynthesis
    1. Protons and neutrons combined to form light elements Hydrogen and Helium
    2. Other light elements such as Lithium and Beryllium were also formed during this process
  • Nebula
    Giant cloud of gas and dust
  • Formation of a protostar
    Gravity pulls Hydrogen gas together until it spins faster and faster and becomes ignited
  • Formation of a main sequence star
    1. Nuclear fusion occurs at the core, it begins to contract, glow and become stable
    2. Hydrogen is converted into Helium
  • Formation of a red giant
    1. Star is unable to generate heat when it runs out of hydrogen in its core, leading to its contraction and expansion
    2. Helium fused into Carbon
    3. Star cools down and glows red
  • Formation of a white dwarf
    1. Red giant star becomes exhausted of nuclear fuel, the outer material is blown off into space leaving the inert Carbon
    2. The remnant is known as a white dwarf
  • Formation of a black dwarf
    The hypothetical remnant of a white dwarf that has cooled down and no longer emits light and heat
  • Formation of a red supergiant
    1. More massive main sequence star evolves, cools and expands faster than low mass star
    2. Carbon fusion still occurs and Oxygen formed
  • Supernova
    Explosion of star releases large amount of energy, dispersing elements into space
  • Neutron star
    Formed from supernova explosion, the smallest star
  • Black hole
    Region in space where gravity is too strong that no matter can escape from it
  • Proton-proton chain reaction
    1. Proton and neutron fuse to form deuterium
    2. Deuterium fuses with another proton to form Helium-3
    3. Two Helium-3 atoms fuse to form Helium-4
  • CNO cycle
    Carbon, Nitrogen, Oxygen cycle used by massive stars to convert Hydrogen into Helium
  • Tri alpha process

    Three Helium-4 atoms are converted into Carbon in red giant stars
  • Alpha ladder process
    Fusion of alpha particles in the core of a red supergiant creates heavier elements up to Iron
  • Neutron capture
    A neutron is added to a seed nucleus to form a heavier nucleus
    1. process (slow process)

    Slow rate of neutron capture, faster rate of radioactive decay increases the proton number by 1
    1. process (rapid process)

    Faster rate of neutron capture before radioactive decay, more neutrons can be combined in the nucleus, occurs in supernovae
  • Supernova is the source of elements heavier than Iron, which are dispersed into space
  • Evidence of star formation includes energy emitted during nuclear reactions, including ultraviolet, infrared, X-ray, radio wave and microwave
  • Atomic number

    The number of protons (positively charged particles) in an atom
  • In 1913, Henry Moseley demonstrated that the atomic number determines most of the properties of an element
  • In 1919, Ernest Rutherford successfully carried out a nuclear transmutation reaction, transforming one element or isotope into another
  • In 1925, there were four unknown elements in the periodic table that corresponded to atomic numbers 43, 61, 85, and 87
  • Particle accelerator
    Device used to speed up protons to overcome the repulsion between protons and target atomic nuclei, used to synthesize new elements
  • Transuranium elements

    Elements with atomic numbers greater than 92 (atomic number of uranium), discovered in the laboratory
  • Mendeleev's periodic table

    Classification of elements based on their atomic weight, demonstrating a periodic pattern of physical and chemical properties
  • Hydrogen is the lightest element on the periodic table, with an atomic mass of 1.00794 amu
  • Hydrogen is the most abundant element on the periodic table
    1. x-ray spectroscopy

    Method of identifying elements by shooting electrons at them and measuring the X-rays they emit
  • Moseley's experiments showed that the frequency of X-rays emitted by an element is proportional to its atomic number
  • The gaps in Mendeleev's periodic table corresponding to atomic numbers 43, 61, 85, and 87 were later filled by synthesized elements
  • Nuclear transmutation
    Transformation of one element or isotope into another element
  • The first nuclide prepared by artificial means was an isotope of oxygen, 17O, made by Rutherford in 1919</b>
  • Neutrons are used instead of positively charged particles to synthesize new elements, as they do not repel the target atomic nuclei
  • Technetium (Tc) was the first man-made element, synthesized by bombarding molybdenum with deuterons