Origin of Universe and Big Bang Theory

Origin of the Universe: Big Bang Theory

• Widely accepted theory of the universe's formation
• First proposed in 1920 by Belgian astronomer Georges Lemaître
• Initially known as the "primeval atom" theory
• Occurred approximately 13.7 or 13.8 billion years ago
• All matter and energy were contained in a compact point called "singularity"
• An imbalance within the singularity caused an explosion
• The explosion scattered matter and energy in all directions
• The Big Bang resulted in an expanding universe

Evidences of the Big Bang

• Redshift
  • American Astronomer Edwin Hubble proved that light emitted by distant galaxies shifts toward the red end of the spectrum when observed from Earth
  • Redshift indicates the universe is expanding and galaxies are moving farther away
• Cosmic Background Radiation (CMB)
  • Thermal leftover radiation from the transition phase when the early universe cooled enough for atoms to combine
  • Discovered by Robert Wilson and Arno Penzias
  • Measurable degrees of inconsistencies exist in CMB
• Abundances of Light Elements
  • Actual abundances of hydrogen and helium match what was expected from Big Bang reactions

Big Bang Theory: Singularity

• Initial state of the universe with all matter, energy, space, and time compressed into an incredibly hot and dense point
• Considered the starting point of the universe, from which it began expanding approximately 13.7 or 13.8 billion years ago
• Marks the start of the Big Bang Theory
• The black hole singularity is unlike the Big Bang singularity because it is not in space, but expanded with space itself
• Characterized by infinite density and temperature

Big Bang Theory: Inflation

• Refer to a period of extremely rapid expansion in the universe's early moments
• The space itself stretches exponentially
• Inflates the universe by a factor of 10^26 in a fraction of a second
• Rapid expansion smoothens out wrinkles (inconsistencies) and leads to homogeneity
• Resolves several problems with the standard Big Bang model:
  • Flatness Problem
  • Horizon Problem

Big Bang Theory: Formation of Matter and Antimatter

• Energy constantly fluctuated into short-lived pairs of particles and corresponding antiparticles in the early universe
• Electrons and positrons, and quarks and antiquarks pairs formed
• Particles and antiparticles annihilate each other almost instantly, releasing energy back into the environment
• Matter and antimatter are always produced as a pair
• Particles and antiparticles cancel each other out completely
• Temperature is hot and dense, resulting in constant activity

Big Bang Theory: Nucleosynthesis

• Thermonuclear reaction that produces a new chemical element from another element
• As the universe cools, protons and neutrons fuse to form heavier atomic nuclei
• Light elements are formed through nuclear reactions located in the core of stars during cosmic events

Big Bang Nucleosynthesis

• "Primordial Nucleosynthesis" pertains to the formation of light elements (H, He, and traces of Li) in the early universe
• The temperature was very high in the early universe, so all matter was fully ionized
• Ionization is the process by which electrically neutral atoms or molecules gain or lose electrons, forming charged particles called ions

Series of Reactions

• Protons and neutrons fused to form DEUTERIUM
• Deuterium collided with other protons, producing helium-3
• Deuterium fused with neutrons to produce tritium
• Tritium and two deuterium nuclei collided and formed lithium-7
• Helium-3 collided with neutrons, forming helium-4

Stellar Nucleosynthesis

• Timeline includes a stage of galaxy formation
• Galaxy → gravitationally bound system of stars, stellar remnants, interstellar gas and dusk, and dark matter
• A star generates its energy by fusing light nuclei to form a heavier nucleus
• Mass is converted to energy during this process, according to Einstein's equation (E=mc^2)
  • E = energy, m = mass, and c = speed of light (3 x 10^8 m/s)

Dark Matter and the Solar System

• Dark matter (hypothetical kind of matter) cannot be observed, even with telescopes.
• Sun in the solar system → formed because of gas and dusk collapses due to gravity
• Converts gravitational energy to real energy, causing the center to glow
• The temperature will be high enough to create nuclear reactions which begin at the core of the star and sun
• Fusion of four hydrogen nuclei create a helium nucleus
• Heavies elements are formed: Li to Fe (iron)

Hydrogen Burning Phase

• Commonly referred to as the hydrogen burning phase
  • the proton-proton cycle
  • the carbon-nitrogen-oxygen (CNO) cycle
• CNO Cycle = creation of massive stars

Supernova Nucleosynthesis

• Involves the production of new elements during a supernova
• A supernova is an explosion of a massive star (5-10 times the mass of the sun) when it runs out of nuclear fuel
• A high concentration is produced and discarded

The Creation of New Elements

• Rapid neutron capture rises to neutron rich isotopes
• heavy elements have been made
• Highly unstable isotopes are created
• Giant stars are formed and the universe cools down

Steady State Theory

• Everything in the universe is constant and uniform

Nucleosynthesis

• Heat death → universe is a rich state where everything evens out
• Slows down where everything is less energetic and spread out

Particle Annihilation

• Opposites of matter and antimatter meet, they annihilate each other, and the result is that they are converted to pure energy

Recombination

• Protons and electrons combine to form hydrogen in this stage
• Helium nuclei (alpha particle) combine with electrons to form helium atoms
• Temperature lowers to wherein both protons and electrons form hydrogen
• Releases protons of light, which protons are quantum of light and is mass-less

Dark Ages

• Lasted for millions of years while the universe expanded
• Matter started to clump together due to gravity
• It is the stage in history where everything is mostly dark
• First generation of stars (population III stars) formed in this time
  • First stars were made of matter that clumped together over time

Atomic Nucleus

• Matter is made out of atoms

• Matter is made with: electrons, protons, neutrons Consists of

• Positively charged nucleus in the center

• Nuclear protons and neutrons

• Nucleons

Ernest Rutherford and the Nuclear Model of the Atom

• Discovered the nuclear model of the atom
• Found that atoms have a small, dense nucleus with electrons orbiting around it
• Replaced the earlier idea that electrons were just spread out inside the atom
• Shot alpha particles (helium) at a thin sheet of gold

Rutherford's Findings:

• Majority of helium went through the gold foil
• Observed small deflection with flashes of light
• Setup was a He shot of alpha particles (helium nuclei) to a thin gold foil
• Most particles passed straight through without being seen
• Some deflected slightly and very few bounced straight back

Rutherford's Conclusion:

• Led to the nuclear model of the atom
• Proposes electrons orbit a central nucleus instead of being spread out inside
• Small nuclide leads to some small deflection(s) with 1/20,000 bounces back observed
• Behavior shows that gold atom is positively charged to a measurable degree
• The deflection means atom had tiny, dense, positively charged nucleus that repelled some alpha particles
• Vast majority of helium passed, as atoms were mostly empty space

J.J. Thomson and the Plum Pudding Model

• Proposed The Plum pudding
• Predicted Particles will pass through
• Model proposes atom a sphere of damage and and tiny is charges

Thomson and the J.J. Model

• Consists of a positive: sphere made of positive charge
• Is balanced by electrons
• The atom is a making neutrons
• The model shows electrons randomly scattered by watermelons

Thomson's Incorrect Prediction(s)

• J.J. Thomson proposed atom a "plum pudding" (or a watermelon)
• Model puts atoms positively charged sphere (like the soft part of a pudding or the red part of a watermelon)
• Randomly scatters Electrons are tiny, negatively charged, inside similar to raisins pudding or black seeds watermelon
• Model shows since positive and negative charges are balanced, then, atom as a whole is neutral
• This led to model predicting particles should pass through w/o deflection
• The Rutherford experiment disproved this model with its showing dense, central nucleus

Isotopes

• Exists as elements with the same number of protons - Isotopes have different numbers of neutrons/mass number

• They do not change the flavor of the element

• Proton levels stay the same and this is the deciding factor of this specific isotope element

• Neutrons provide difference between each variety of elements Isotopes change isotopes/mass but not deciding element

• Carbon 12 has 6 neurons

• Caron-13 has 7 neutrons

• Carbon-14 has 8 neutrons

• Change isotopes is like changing texture of taste of ice cream, but not flavor → Atomic Number (Z) = number of protons (P) → Mass Number (A) = number of protons + number of neutrons (P + N) → A-Z = number of neutrons → Number of electrons = Number of protons (E = P) → Atomic charge = number of protons - number of electrons (P - E)

Balancing Nuclear Equations

• Changes to nuclei result in changes to atomic, mass, energy levels or nuclear reactions
• Changes in chemical: rearrange the elements which still remain the same Change is nuclei change the element + Conserves mass in nuclear reactions via law of conservation Changes in Fusion and fission nuclear reactions

Nuclear Reactions and the Specific Types, Explained

Alpha Decay: losing an alpha particle (helium nuclei)

• A Beta Decay: losing a beta particle occurs
• Gamma Radiation: causes emission of a gamma ray
• Emission a positron: causes protons in the nuclei to lose an alpha neutron
• Capture involves drawing an electron into atom with a nucleus
• Bombardment of Alpha Particles: the addition of alpha particles

Molecular compounds and the Intermolecular and Intramolecular Bonds

Molecular Formula: Intramolecular forces Intramolecular forces = forces hold atoms together molecule Intramolecular - forces also present between molecules

Balancing Equations, cont, and the Relation to a Charge

• Consists of alpha reactions reactants + before and products + after
• Capture causes something release
• An Atom that has an unequal number of protons and or unequal number of electrons forms a molecule; atoms in the process sacrifice electron to form a molecule of stability

Compounds and their relation to a Charge

• The Substance that consists of single atoms → not bonded to another atom has an equal change
• Depending on charge, these compound categorized into
  • cat paws = positive forms molecule
  • anions cry = negative charges, has a charge

Polyatomic and Ionic Compounds

• Polyatomic are compounds made up of of 2 plus atoms of ions
• Polyatoms are known as the molecule ion
• It includes multiple atoms that bonder in the compound Depending, the atoms grouped into cations and anions with equal amounts elements

Covalent Bonding Explained

• It formed through sharing electrons between pair atoms → exists in nature
• It could be polar or nonpolar bonding Transfer electrons: but here sharing = compound Pareho silang gumagamit nagco-contribute

Covalent Bonds are a Mixture

• The results are atoms sharing electrons
• Molecule bonds creates 2 hydrogens → outer shell needs molecule for bonds
• nagshare and same contributing
• The Molecule is pure compound of covalant

Ionic and Covalent Bonds

• Interactions between: forces bonds atoms
• Intramolecular forces the molecule are forces hold together within molecule
• The molecule exists

Molecule Compounds, Ionic or Covalent

• lonic bonds have mix or metal and nonmetal
• Ionic occur between molecular and held together by charge differences
• Covalent Bonds do not exists metal(iods and aids compounds, or metals, instead covalent have non-metal bonding → these metals are considered nonmetal and can act as metal by compound type

The Concept of Polar and Nonpolar Molecule:

The atom is equally

• Bonding electrons molecule between atoms
• No charges can exists to balance it all, monoatomic, or diatomic compounds
• Contain carbon and hydrogen in compound symmetrical outer

Concept of Polarity: Polar Compound and the Asymmetrical

Bonding Atoms share electrons unequally Unequal partial exist in atom as positive or negative charges Unequal charge exists on atoms

• Hydrogen loses the electron is positive
• Compound: hydrogen is direct and polar The presence of molecules with the alcohol bond: methanol
• If is has asymmetrical components which make elements polar

Type of the Molecular Structures

• Contains a transferring electronics
• Full charges exists resulting in ions

Polar Molecules: Charge and Effects

• Has tendency an atom to attract elerons itself is molecule
• Increasing negativity Electronegativity Difference affect how bonds formed
• Absorb negative charges lonic bonds form in this bond, automatic positive
• Has a Polar covalent force-strength
• Also Nonpolar form bond with zero power

Structure of the Molecules

• Ways to represent the valence electrons of atoms molecules is with a certain structure
• Atoms do form bonds and are represented with structure to compound
• Helps visualize how structure formed bond and share molecules covalent compounds

The Valence of a Atom and the Concepts of Atomic Structure

Valence Electrons (electrons in the outermost energy level of an atom)

• Involved atomic bonding and valence Octet Rule - atoms gain, lose, or share electrons to achieve eight valence electrons 8 valence needed
• Atoms share electrons form a stable element, hydrogen and helium:
  • atoms bond, stable long-term

Single, Double, Single Bonds

Atoms can't form single (one pair), double (two pairs), or triple (pairs

• Single Alkanes
• Double Alkenes
• Triple Alkynes

Molecular Structures

• Determine (what + cation/anion), and in what quantity: (10%, +-, +-) etc
• Note the charge differences for each atom and balance the charges by adding subscripts
• These reactions are called reactions in: A + BC → AC+B

Writing LEDS

Draw skeleton structure of compounds showing what is bonded Place least electronegative atom at the center

• Central VS Outer Use pair electronics form bomb between band atoms arrange 1, 8 atoms

Structures and Models

• Gilbert Newton Lewis describes that uses dots for symbol with its related atoms or compounds

• Determine Bond type with Valence electron
• Draw arrangement and correct bands Reaching chemical compound is achieved by add reactants Subtract to cancel

Polar Molecules and Their relation to Bond Composition

• Atoms combine together in molecules
• Imagine for making sandwich, the two slices of bread and two pieces
• atoms combine to form the compound
• The Molecule cannot destroy

Bohr

• Electrons move to nucleus; energy levels
• Electrinos like plane around
• Electrons orbit nucleus: planate with orbiting molecule
• Each orbit level has a specific energy
• Electrons can dump higher releases

Shrdinger's Theory

Electron fixed in a circle with orbit instead cloud -like

• Cloud shows electrons likely appear Fixed electrons is not move with Bohr Mathematical show electrons

Electrons move as particles but time is not on there

B Atoms

• Form stability in bond Has a bond types , covalent/metaling elements versus compounds:
• Oxygen and help only contain isotopes
• Subscript Na 2

Type of Covalent- Only contain this

• Oxygen, has contain the diatomic
• Contains other types from atoms and other isotopes

Moleculars: Nonmetal

• Two molecules that forms