Physical Science Midterm Examination Reviewer

REVIEWER **MIDTERM EXAMINATION** PHYSICAL SCIENCE - Carbon formed during the fusion of three helium nuclei - The atomic number of an element is the number of protons in its nucleus. - The difference between an element and an isotope is an element is a pure substance made up of onl...

REVIEWER **MIDTERM EXAMINATION** PHYSICAL SCIENCE - Carbon formed during the fusion of three helium nuclei - The atomic number of an element is the number of protons in its nucleus. - The difference between an element and an isotope is an element is a pure substance made up of only one type of atom, while an isotope is a variation of an element with a different number of neutrons. - Nuclear fusion is the primary source of energy for a star? - Isotopes provided a way to identify the different forms of an element based on their atomic mass. the discovery of isotopes contributes to the understanding of atomic structure and the synthesis of new elements - the discovery of the concept of atomic number contribute to the understanding of the periodic table by allowing scientists to identify the properties of new elements and determine their position in the periodic table. - The role of nuclear fusion in the formation of heavier elements during star evolution is it converts lighter elements into heavier ones. - Scientists use particle accelerators to synthesize new elements by bombarding a target element with high-energy particles to create a heavier nucleus. - The electronegativity difference between the atoms in the molecule is the main factor that determines whether a molecule is polar or nonpolar? - The Lewis Structure of H~2~O (water) - Surface tension is the resistance of liquid to increase its surface area. - viscosity is the measure of the resistance of a liquid to flow - The alcohol dries faster than water because alcohol is more volatile than water. - macromolecules are also known as biomolecules or large biomolecules that provides us with the building blocks that we need to maintain homeostasis. - The following are the 4 basic types of macromolecules found in living things are Carbohydrates, lipids,proteins and nucleic acid - Lipids are the molecules that includes fats, oils, waxes and cholesterol? - Collision Theory states that for a chemical reaction to occur, the reacting particles must collide with one another. - Polar molecules are more soluble in polar solvents. - The general types of intermolecular forces are Hydrogen bonding, Dipole-dipole interactions, dispersion forces - The primary difference between hydrogen bonding and dipole-dipole interactions, Hydrogen bonding involves the attraction between a hydrogen atom and a strongly electronegative atom, while dipole-dipole interactions involve the attraction between two polar molecules. - If you store your leftover foods inside the refrigerator the food will not immediately spoil because of the cold temperature. - If you burn dried leaves during summer, a dry strong wind will fan and scatter the fire in the forest.that will contribute and result in a forest wildfire. - Catalyst is a substance that increases the rate of a chemical reaction. - Certain molecules in saliva helps us digest food, such as amylase. Amylase speeds up the reaction of the conversion of starch into maltose. Amylase represents a catalyst. - The black enamel paint coating of the large gatehouse fronting the abandoned mansion has peeled off in time. The gatehouse that was made of iron metal will eventually rust if not repainted soon. - Chemistry is the study of quantitative relationships involved in chemical reactions - "Go Foods" like carbohydrates are the type of food that provides fuel and help us \'go\' and be active..we will feel weak when we didn't have rice in his meal. - A chemical change happens when a substance's chemical identity changes examples of chemical change are digestion, photosynthesis and rusting. Boiling water is an example of physical change. - Combustion or burning is a chemical reaction in which oxygen is a reactant. A greater concentration of oxygen in the air make combustion more rapid if a fire starts burning. if you want to make a camp and after igniting the tinder with a lighter, it caught spark and started smoldering (smoke without fire) blow some air into the smoldering tinder to feed it with oxygen. - Food spoils because of chemical reactions, and these reactions occur faster at higher temperature. Therefore, we store foods in the refrigerator or freezer. The lower the temperature slows the rate of spoilage. - To make an iced coffee, dissolve the coffee powder in a lukewarm water first before mixing it with ice. - NH~3~ polar molecule - The shape of a molecule affects its polarity. A symmetrical shape results in a nonpolar molecule, while an asymmetrical shape results in a polar molecule. - the polarity of molecules be polar or nonpolar regardless of its bond type. - CCl~4~ is a nonpolar molecule - Like dissolves like. Polar solutes tend to dissolve in polar solvents. Nonpolar solute dissolves in nonpolar solvent. - Boiling point, solubility in water and melting are the properties affected by the polarity of a molecule - Polar molecules have a higher boiling point than nonpolar molecules because The polar molecules have a stronger intermolecular attraction. k