Physical Science Review PDF

Review Oganesson (Og) is the heaviest known element on the periodic table. Plasma is formed when the core of a star is heated Bohr developed the model of the atom that is widely accepted today. Fluorine and chlorine form a polar covalent bond...

Review Oganesson (Og) is the heaviest known element on the periodic table. Plasma is formed when the core of a star is heated Bohr developed the model of the atom that is widely accepted today. Fluorine and chlorine form a polar covalent bond due to the difference in their electronegativities. In a non-polar covalent bond, electrons are equally shared between atoms. Ammonia (NH3) is a polar molecule due to its shape and bond polarity. O2 molecules are held together by covalent bonds. London dispersion forces are present in all molecules, regardless of polarity. Glucose is the form of carbohydrate that body cells readily absorb. A disaccharide is made up of two sugar units. Every collision in a chemical reaction involves the transfer of energy. Activation energy is the minimum energy required for a reaction to occur. Excess reactants are not used up at the end of the reaction. Methane is the main constituent of biogas. Geothermal energy is heat produced from within the Earth. Additives are substances added to improve or preserve products. A pH adjuster balances acidity in a product. Atomic weight is determined by the number of protons and neutrons. Carbon and sulfur form a nonpolar covalent bond due to their similar electronegativities. Ion-dipole forces are the strongest among the listed intermolecular forces Water supplies electrolytes, which are essential for body function. Carbon is a key component of carbohydrates. A catalyst increases the rate of a chemical reaction. Higher temperature increases the rate of a chemical reaction. In a chemical reaction, reactants are converted to products. A chemical reaction stops when the limiting reactant is exhausted. An endothermic reaction absorbs energy from its surroundings. Hydrothermal plants use heat from deep within the Earth. Bleach is commonly used as a disinfectant. Cyclotrons are used to synthesize rare elements like astatine. Stellar nucleosynthesis in star cores forms light elements like hydrogen and helium. Heating water continuously will cause it to turn into gas (steam). Water’s high melting and boiling points are due to strong hydrogen bonds.  Water’s hydrogen bonding contributes to its temperature regulation and solvent properties. Polar molecules interact strongly with each other due to dipole-dipole interactions. Waxy coatings help plants conserve water by limiting water loss. Lowering temperature slows down the rate of a chemical reaction.  Coal is formed from plant material under high pressure and temperature over geological time. Detergents with grease-cutting agents are most effective for removing dirt and grease. Baking soda absorbs oil, making cleanup easier. Heavier elements are formed during stellar nucleosynthesis. Strong intermolecular forces increase viscosity. Genetic sequencing is the most effective method for analyzing evolutionary relationships. Higher temperatures generally speed up decomposition reactions. To accurately prepare a chemical reaction, quantities should be converted to moles. Additives improve the quality and shelf life of products. The Hertzsprung-Russell diagram accurately depicts a star’s luminosity Polar substances are more effective for bonding various materials due to stronger intermolecular forces.