Phy Sci

• BIG BANG THEORY – the most widely accepted theory about the origin of the universe
• BLACK HOLES – are areas of intense gravitational pressure where matter is condensed to an infinite density
• HUBBLE’S LAW of COSMIC EXPANSION – states that in an expanding universe the distant galaxies we see in all directions are moving away from Earth
• BIG BANG NUCLEOSYNTHESIS – also known as PRIMORDIAL NUCLEOSYNTHESIS is believed to be the process that formed deuterium, tritium, helium-3, helium-4, lithium-7, and beryllium-7
• DEUTERIUM – is an isotope of hydrogen that has one proton and one neutron which is considered marginally stable.
• TRITIUM – is a radioactive isotope of hydrogen, which has one proton and two neutrons; it is formed from the fusion of two deuterium nuclei, accompanied by a release of a proton
• LITHIUM-7 – is an unstable atom formed during BBN; it is produced from the nuclear fusion of helium-4 and tritium
• BERYLLIUM-7 – an unstable atom formed during BBN; it is produced from the nuclear fusion of helium-3 and helium-4
• HELIUM-4 – is a stable atom with a binding energy equivalent to 28 MeV
• PROTON – the positively charged subatomic particle
• ELECTRON – the negatively charged subatomic particle
• NEUTRON – the neutral subatomic particle
• ATOMIC NUMBER - represents the number of protons in an atom
• MASS NUMBER – represents the number of protons plus the number of neutrons
• Computing for number of neutrons: # of neutrons = Mass number – atomic number
• NUCLEAR TRANSMUTATION REACTION – a reaction involving the transformation of one element or isotope into another element
• PARTICLE ACCELERATOR – is a machine that propels charged particles to nearly the speed of light
• ALCHEMY – a philosophy practiced throughout Egypt and Eurasia aimed to purify and perfect materials through transmutation
• LEWIS DOT STRUCTURE –the notation used in representing the valence electrons of elements
• OCTET RULE – states that atoms tend to lose, gain, or share electrons with other atoms in order to have a stable configuration of 8 valence electrons
• INTRAMOLECULAR FORCES – also known as bonding forces ; they exist within each molecule and influence the chemical properties of the substances.
• INTERMOLECULAR FORCES – also called van der Waals forces ; forces that exist between the molecules and are also responsible for the physical properties of substances
• ION-DIPOLE ATTRACTION – happens when an ion attracts a nearby polar molecule
• HYDROGEN BOND – is a special type of dipole-dipole force that exists between molecules that have a hydrogen atom bound to a small, highly electronegative atom with lone electron pairs
• SURFACE TENSION – this property is the result of the difference between the IMFA in the interior of a liquid and the IMFA at the surface of the liquid
• CAPILLARITY – this property refers to the rising of a liquid in a narrow container against gravity
• VISCOSITY – refers to the resistance of a liquid to flow
• ACTIVATION ENERGY – the minimum energy required for breaking the bonds in the reactants and forming new bonds to create bonds.
• CATALYST – a substance that can be added to a chemical to enable the chemical reaction proceed faster
• ENZYMES – are highly specific and efficient biological catalysts
• RADIOACTIVITY - is the release of energy, in the form of energetic particles and waves, from the nuclei of unstable (radioactive) isotopes
• VALENCE ELECTRONS - are defined as electrons in the atom’s outermost orbital
• About 98% of the universe is composed of hydrogen and helium, making these two the most abundant elements.
• FUSION REACTIONS are always accompanied by tremendous release of amount of light, heat, and radiation.
• When fusion reactions happen inside stars, the process is known as STELLAR NUCLEOSYNTHESIS.
• The Law of Multiple Proportions is a rule of STOICHIOMETRY
• Matter is composed of indivisible building blocks called ATOMS.
• ANTOINE LAVOISIER – described the LAW of CONSERVATION of MASS
• JOSEPH PROUST – proposed the LAW OF DEFINITE PROPORTIONS
• JOSEPH JOHN THOMPSON – discovered ELECTRONS; proposed the PLUM PUDDING MODEL of an atom