Biology 110 exam 1 - marla perez exam with multiple choices questions and answers solutions guaranteed|

matter - correct answers Anything that has mass and takes up space atoms - correct answers smallest unit of matter (form chemical substances) subatomic particles - correct answers protons, neutrons, electrons protons - correct answers positive charge; found in nucleus neutrons - correct answers no charge (neutral); found in nucleus electrons - correct answers negative charge; found outside/around nucleus # of protons - correct answers atomic number; distinguishes one element from another orbitals - correct answers regions surrounding the nucleus in which there is a high probability of finding an electron S orbital - correct answers spherical, 2 electrons P orbital - correct answers dumbbell shaped, 6 electrons electron shells - correct answers An energy level representing the distance of an electron from the nucleus of an atom. The energy level of each shell increases with distance from the nucleus. Electrons can be found in different shells. Periodic table - correct answers A table that shows the elements, their atomic number, symbol, and average atomic mass; elements with similar chemical properties are grouped together. mass number - correct answers Number of protons and neutrons atomic number - correct answers the number of protons in the nucleus of an atom dalton unit - correct answers AMU; unit of measurement for atomic mass mole - correct answers the SI base unit used to measure the amount of a substance; 1 mole of any element contains the same number of atoms avogadros number - correct answers 6.02 x 10^23 isotopes - correct answers Atoms with the same number of protons but different numbers of neutrons radioisotopes - correct answers Isotopes that have unstable nuclei and undergo radioactive decay. valence electrons - correct answers Electrons on the outermost energy level of an atom octet rule - correct answers atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons; atoms are stable when their outer shell is full molecule - correct answers 2 or more atoms bonded together molecular formula - correct answers formula giving the number of atoms of each of the elements present in one molecule of a specific compound compound - correct answers any molecule composed of 2 or more elements chemical bonds - correct answers the attractive forces that hold atoms together types of bonds - correct answers ionic, covalent, hydrogen covalent bond - correct answers two or more atoms held together by covalent bonds constitute a molecule. strong chemical bond because shared electrons behave as if they belong to each atom; can be polar covalent or nonpolar covalent single bond (covalent) - correct answers sharing one pair of electrons (single line) double bond (covalent) - correct answers sharing of two pair of electrons (double line) triple bond (covalent) - correct answers 3 pairs of valance electrons being shared electronegativity - correct answers an atoms attraction to electrons *more* electronegativity - correct answers the more electronegativity an atom has, the more strongly it pulls shared electrons towards itself nonpolar covalent bonds - correct answers equal sharing of electrons; atoms with similar electronegativities polar covalent bonds - correct answers unequal sharing of electrons; atoms of diff. electronegativity ion - correct answers an atom/molecule that has gained or lost one of more electrons ionic bonds - correct answers occurs when a cation binds to an anion by electrostatic attraction cation - correct answers A positively charged ion anion - correct answers A negatively charged ion weak chemical bonds - correct answers ionic bonds, hydrogen bonds, and van der Waals interactions hydrogen bond - correct answers attraction between a hydrogen atom from one polar molecule to an electronegative atom of another - individually weak, collectively can be strong - holds DNA strands together van der Waals forces - correct answers a slight attraction that develops between the oppositely charged regions of nearby molecules - unevenly distributed chemical reactions - correct answers one or more substances are changed into other substances reactants - correct answers starting molecules in chemical reaction products - correct answers final molecules of a chemical reaction properties of chemical reactions - correct answers - needs energy - require an enzyme as catalyst (in living things) - eventually reaches equilibrium - occur in liquid hydrogen bonding - correct answers gives water properties that help make life possible on earth solution - correct answers a liquid that is a homogeneous mixture of substances solvent - correct answers the dissolving agent of a solution solute - correct answers substance that is dissolved aqueous solution - correct answers one in which water is the solvent hydration shell - correct answers the sphere of water molecules around each dissolved ion hydrophilic - correct answers Having an affinity for water. Hydrophobic - correct answers Water fearing amphipathic molecule - correct answers have both polar or ionized regions at one or more sites and nonpolar regions at other sites molarity - correct answers the number of moles of solute per liter of solution antifreeze - correct answers lowers freezing point, some animals produce antifreeze molecules hydronium - correct answers H3O+ ; proton (H+) binds to the other water molecule acids - correct answers molecules that release hydrogen ions in a solution bases - correct answers Compounds that reduce the concentration of hydrogen ions in a solution. buffers - correct answers weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH macromolecule - correct answers large, complex organic molecules - carbohydrates - lipids - proteins - nucleus acids organic molecules - correct answers molecules that contain carbon Hydrocarbons - correct answers organic molecules consisting of only carbon and hydrogen chemical groups - correct answers can replace one or more of the hydrogens bonded to the carbon skeleton functional groups - correct answers groups of atoms with special chemical features that are functionally important isomers - correct answers 2 molecules with an identical molecular formula but different structures and characteristics structural isomers - correct answers contain the same atoms but in different bonding relationships stereoisomers - correct answers identical bonding relationships, but the spatial positioning of the atoms differs in the two isomers cis-trans isomers - correct answers carbons have covalent bonds to the same atoms, but the atoms differ in their positioning around double bond enantiomers - correct answers are isomers that are mirror images of one another polymer - correct answers long molecule consisting of many similar building blocks monomers - correct answers small building block molecules within polymers enzymes - correct answers Proteins that speed up chemical reactions carbohydrates - correct answers serve as fuel and building material; includes sugars and polymers (chains) of sugars. (composed of carbon, hydrogen, and oxygen atoms) monosaccharides - correct answers simplest sugars; serve as a major nutrient for cells and as raw material for building molecules. EX: glucose Strucutral Isomers - correct answers different arrangement of same elements disaccharides - correct answers are carbohydrates composed of two monosaccharides polysaccharides - correct answers are many monosaccharides linked together to form long polymers Lipids - correct answers are a diverse group of hydrophobic molecuses; includes fats, phospholipids, steroids, waxes