Physical Science Reviewer PDF

REVIEWER PHYSICAL SCIENCE  Stars derive their energy from the fusion of elements within their core. This fusion process primarily involves the conversion of lighter elements into heavier ones. Among the given options, the correct elements for stellar fusion...

REVIEWER PHYSICAL SCIENCE  Stars derive their energy from the fusion of elements within their core. This fusion process primarily involves the conversion of lighter elements into heavier ones. Among the given options, the correct elements for stellar fusion are: o Hydrogen and Helium  At what stage in their life cycle do stars typically create heavier elements other than iron? o Supernova  Which of the following provides evidence that heavier elements are formed during the evolution of stars? The detection of spectral lines corresponding to heavier elements in supernova remnants.  Which process is primarily responsible for the formation of elements heavier than iron (Fe) during star evolution? The rapid neutron capture process (r-process) during supernova explosions  Which product is NOT generated by the proton-proton chain reaction in stars? Oxygen-16 (16O)  Which option concludes the reaction? 2 98  1 + 42 → ___ + 10 o 9742  How is the link between an element's location in the periodic table and the frequency of X- rays it emits related? The number of electrons of the atom is the same as the frequency of spectral lines in the X-ray.  Ernest Rutherford successfully carried out a nuclear transmutation reaction in the synthesis of elements? He showed that the nitrogen nuclei reacted with the alpha particles to form oxygen nuclei.  How did the discovery of the atomic number reshape scientists' approach to synthesizing new elements in the laboratory? It revealed that the number of protons in a nucleus determines the identity of an element, guiding targeted proton addition to synthesize new elements.  Which statement best explains how the concept of atomic number enabled the use of chain reactions to create super heavy elements? Understanding atomic number allowed scientists to target nuclei with specific proton counts, initiating a chain reaction that resulted in the formation of new element  How is the frequency of the X-ray spectral lines that were used to demonstrate the number of protons related to the atomic number? The square root of the frequency of emitted X- rays is approximately proportional to the atomic number.  A neutral atom of an element has 2 electrons in the first energy level, 8 in the second energy level and 8 in the third energy level. This information does not necessarily tell us: the number of neutrons in the nucleus of an atom of the element.  Which of the following molecules is polar due to its molecular geometry? Water (H₂O)  A molecule is formed between two atoms with the following electronegativities: Atom A = 3.0 and Atom B = 2.1. Based on this information, is the molecule likely to be: Polar, because there is a significant electronegativity difference.  Why do covalent compounds tend to be liquid and gases at room temperature? It is due to the weak forces of attraction between molecules.  Which of the following atoms when bonded with Fluorine atom, produces the highest degree of polarity? Oxygen  Which of the following molecules does NOT have polar covalent bonds? CS2  Which of the following bonds is the most polar? N-F  If a molecule of H2S has a bent geometry, which of the following is correct? o It is a polar molecule. I. Which of the following changes would increase the vapor pressure of a liquid? II. an increase in temperature III. an increase in the intermolecular forces in the liquid 1  IV. an increase in the size of the open vessel containing the liquid  I only  Which of the following correctly identifies and describes a type of intermolecular force? o Dipole-dipole forces: Attractions between the partial charges of polar molecules.  Which statement best compares the strengths of the general types of intermolecular forces? Hydrogen bonding is stronger than dipole-dipole forces but weaker than covalent bonds.  The image on the right shows examples of molecular geometries and types of intermolecular forces. Based on the image, identify which intermolecular force is described in the following scenarios:  Hydrogen bonding occurs between molecules with which of the following combinations? H₂O and H₂O  London dispersion forces dominate in which of the following scenarios?  Nonpolar molecules like CH₄ interacting.  In your experience, what factors do you believe contribute to raising the boiling point of a compound, and how would you apply this understanding in a practical scenario?Intermolecular forces: Stronger forces lead to higher boiling points.  Which of the following would best explain the immiscibility of oil and water? Oil is nonpolar while water is polar,  Which of the following exhibits dipole-dipole attraction between molecules? AsH3  When NaCl dissolves in water, aqueous Na+ and Cl – ions result. The force of attraction that exists between Na + and H2O is called a(n) _____ interaction. ion-dipole  What is the intermolecular force present in LiF?  o None of the above  Why are polar substances generally more soluble in water than nonpolar substances? Polar substances form dipole-dipole interactions or hydrogen bonds with water, which are stronger than the forces between nonpolar substances and water.  Which of the following substances has the highest boiling point, and why? Sodium chloride (NaCl), due to ionic bonds  Which of the following best explains how the structure of glycogen allows it to function as an energy storage molecule in animals? Glycogen's highly branched structure allows for rapid release of glucose when energy is needed, making it an efficient storage form.  How does the double-helix structure of DNA contribute to its ability to store genetic information? The double-helix structure allows for the easy formation of hydrogen bonds between complementary bases, enabling accurate replication and information storage.  Which of the following best explains how the primary structure of a protein (its sequence of amino acids) determines its function? The primary structure of a protein directly determines its three-dimensional shape, which is critical for the protein’s ability to bind to specific molecules or catalyze reactions.  You are studying a newly discovered species and want to study its genetic information. Which biomolecule could provide the needed information? Nucleic Acid  There is a coating of the feathers of waterfowl such as ducks that keeps that keeps them from getting wet. Which molecule would this water –repelling coating be made of? Lipid  Which of the following scenarios best demonstrates how the structure of a protein is linked to its biological function? A misfolded protein loses its function due to the incorrect positioning of its active site for substrate interaction.  Nucleotides are building blocks of nucleic acids, each is a composite molecule formed by? Base- sugar-phosphate  Which statement best explains how the structure of a protein determines its function? The sequence of amino acids determines the protein's three-dimensional shape, which defines its function. 2  Which of the following factors would not affect the rate of reaction? The climate  If you want to increase the concentration of a gas reactant, what would you do? Decrease the space of the gas container.  What would you do if you want to have more space for particle size to collide? Increase the surface area  In order for reactants to form products, they have to overcome what Barrier?activation energy  According to simple collision theory, increasing the concentration of reactants affects the rate of reaction because: It increases the frequency of collisions.  Why does a candle burn more rapidly when placed in an open jar than in air? What accounts for this reaction? Higher oxygen concentration  A student claims that increasing the concentration of a reactant always increases the reaction rate. Evaluate this statement. False, because the rate depends on whether the collisions are effective.  Why does increasing the temperature generally increase the rate of a chemical reaction? It increases the energy of the collisions, making more collisions effective.  Which statement best describes how a catalyst can speed up a chemical reaction? The catalyst makes lower energy pathways available.  How does the presence of a catalyst affect the reaction rate? A catalyst speeds up the reaction by providing an alternative pathway with lower activation energy.  In an industrial process, a platinum catalyst is used to convert reactant A into product B more efficiently. What will happen if the amount of platinum catalyst is doubled? The reaction rate may increase further because more catalyst can provide more active sites for the reaction.  Which of the following statements about catalysts is incorrect? They are consumed during the reaction.  If 5.0 grams of magnesium (Mg) react with 5.0 grams of hydrochloric acid (HCl) according to the reaction below, Reaction: Mg + 2HCl → MgCl2 + H2  What is the mass of the limiting reactant? Hydrochloric acid is the limiting reactant, and its  How many grams of hydrogen gas (H₂) will be formed?  Which source of energy is obtained from animal manure that produces methane needed to generate heat and electricity? biomass  The main reason for the worldwide slowdown in the construction of nuclear power plants is that. The electricity from nuclear power is generally more expensive to produce than electricity from other sources.  Which processes are involved in harnessing energy from biogas? Direct combustion of biogas to generate heat or electricity.  How does hydrothermal energy differ from geothermal energy in harnessing energy? Hydrothermal energy relies on liquid water reservoirs, while geothermal can include dry steam.  Which is produced from organic material like plants and trees and is used for heating, cooking, and fuel? biogas  Which of the following processes occur when energy is harnessed from batteries? Chemical energy stored in the battery is converted into electrical energy through redox reactions.  Which of the following form micelles when placed in water? detergent  Why is it necessary to indicate the active ingredient in product labels of cleaning products? o Because it tells customers how it will work.  Which of the following is always true about active ingredients? They dictate the efficacy of the product for its intended purpose.  Which of the following is an active ingredient found in product labels of bleach? sodium hypochlorite  A toilet bowl cleaner is advertised as removing hard water stains and killing bacteria. Which of these are possible active ingredients? Hydrochloric acid, Sodium hypochlorite  Which ingredient may come in the form of salts, organic reagents, or buffers that maintain pH balance? none of these 3  Which ingredient mask the putrid smell and is used particularly in the bathroom? fragrance enhancers  Which ingredient removes the fragrance of a product applicable for sensitive users? masking agents  Which ingredient is needed by cleaning agents that are stored for a long period to keep the active ingredient functional? preservatives  Which of the following is not an added ingredient of detergents? none of these  Which ingredient is commonly added to cleaning agents to enhance their ability to remove grease, and how does it work? Surfactants: Reduce the surface tension of water, allowing it to mix with oils and grease. 4