Biology 1305 Exam 1 Quigley (Baylor) Questions &Answers

How many valence electrons does Phosphorus have? - ANSWERS5 Two oxygen molecules will form what kind of bond/interaction? - ANSWERSnon-polar covalent What makes a molecule polar? - ANSWERSunequal sharing of valence electrons What property of water allows water molecules to stick together? - ANSWERScohesion What property of water allows water molecules to stick to other substances? - ANSWERSadhesion One of water's unique properties is that its solid and liquid form have the same density. - ANSWERSFalse Water is known as the 'universal solvent.' - ANSWERSTrue High density of ice is a property of water. - ANSWERSFalse You place a paper towel on a puddle of water and notice that water quickly spreads throughout the paper towel. Which property of water is this an example of? - ANSWERSadhesion High surface tension is a property of water. - ANSWERSTrue High polarity is a property of water. - ANSWERSTrue High specific heat is a property of water. - ANSWERSTrue Does water have a higher density on the solid or liquid form? - ANSWERSLiquid What makes a molecule non polar? - ANSWERSequal sharing of valence electrons The atomic number assigned to an element is representative of the number of: - ANSWERSProtons When two carbon atoms are joined to one another by way of a double bond, the atoms found attached to the carbons are... - ANSWERSin the same plane as the carbons what is a compound? - ANSWERSwhen 2 differing atoms bond together Describe an ion - ANSWERSwhen an atom donates its electron to another atom Low specific heat is a property of water. - ANSWERSfalse High surface tension is a property of water. - ANSWERSTrue Water is polar. - ANSWERSTrue Water is cohesive. - ANSWERSTrue Scenario that would cause a covalent bond to form. - ANSWERSTwo atoms share electrons so they can fill their outer shells What does the reactivity of an atom depend on? - ANSWERSpresence of unpaired electrons in the outer valence shell of the atom Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom? - ANSWERS1 You bought a cup of water from Starbucks on a hot, sunny day. As you are drinking water from the straw, you are doing an example of... - ANSWERSadhesion Water Striders are able to stand on water due to which property of water? - ANSWERSsurface tension What do atoms form when they share electron pairs? - ANSWERSMolecules An element has eight protons, nine neutrons, and eight electrons. Its atomic number and atomic mass, respectively, are __________. - ANSWERS8 & 17 Which of the following are compounds? - ANSWERSH20, CH4, but not O2 Atoms have no electric charge because they have ________. - ANSWERSan equal number of protons and electrons A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge. - ANSWERSelectron; neutron Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom? - ANSWERSCarbon has a valence of 4 Research suggests that side effects from Ritalin, the drug used to treat attention deficit disorder, may be caused by contamination of enantiomers, or molecules that - ANSWERSAre mirror images of one another What is the three-dimensional shape created by hybrid orbitals that are formed when a carbon atom is covalently bonded with four other atoms? - ANSWERSa tetrahedron with carbon in the center A pharmaceutical company was forced to recall a pain reliever medication that had been linked to the fatalities of several hundred people. Analysis of the recalled drug revealed the presence of two isomers due to an asymmetrical carbon atom in the drug molecule. What can be hypothesized from this observation? - ANSWERSThe isomers are enantiomers, with one having toxic effects on humans. What is the reason carbon atoms are the most versatile building blocks of the molecules used by living organisms? - ANSWERSEach carbon atom acts as an intersection point from which a molecule can branch off in up to four directions. What is ATP's importance in the cell? - ANSWERSATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes. Which of the following statements is true concerning acids and bases? - ANSWERSacids mixed with bases neutralize each other A hydrogen bond is a polar covalent bond. - ANSWERSFalse To get a hydrogen bond you must have a ____________ bond first. - ANSWERSPolar Covalent Polar molecules have a ____. - ANSWERSCharge Non Polar molecules have _____. - ANSWERSNo charge Hydrogen bonds - ANSWERSan attraction between two different molecules Element has 20 protons and an atomic mass of 45. How many electrons and neutrons? - ANSWERSElectrons-20 Neutrons-25 Covalent bond - ANSWERSThe valence electrons of two atom split their time between the electron clouds of the two. Hydrogen bond - ANSWERSA Hydrogen atom in a molecule is pulled toward the Oxygen atom of another molecule. A Hydrogen bond involves sharing electrons. - ANSWERSFalse A Chlorine atom gains an electron from a sodium atom. - ANSWERSIonic bond Every compound is a ______ , but not every molecule is a _______. - ANSWERSMolecule, compound Molecule vs. compound - ANSWERSMolecule- 2 or more atom Compound- 2 or more elements A Hydrogen bond is always H-H - ANSWERSFalse Bonds in and related to H2O - ANSWERS-2 Polar covalent bonds: between Hydrogen and oxygen and shared electron spends more time with the oxygens. Higher temperature = ______ energy - ANSWERSMore Decreasing energy = - ANSWERSTaking away energy Why is water the "universal solvent" - ANSWERSBecause it is polar covalent with positive and negative ends that can pull apart other molecules How does water regulate coastal temperatures ? - ANSWERSThe water absorbs the majority of heat/energy from the sun so there is little left for the coast What property allows water to regulate coastal temperatures? - ANSWERShigh specific heat Sweating is an example of _______ - ANSWERSevaporative cooling What is special as water forms a solid from a liquid? - ANSWERSThe ice crystals expand How is ice an insulator? - ANSWERSIt floats and becomes a barrier to trap heat. Which is more dense, solid of liquid water? - ANSWERSLiquid Cohesion - ANSWERSWater molecules sticking to each other, surface tension Cohesion & Adhesion - ANSWERS-Help plants transport water -Both reliant on hydrogen bonds Adhesion - ANSWERS-water molecules sticking to other surfaces -Water only sticks to polar molecules how can "water striders" walk on water? - ANSWERS-Cohesion, the hydrogen bonds cause water molecules to stick together -Bugs don't break the surface tension due to their light bodyweight -Their feet have polar molecules so it is adhesive to the water