CHEMISTRY 090 EXAM QUESTIONS WITH ACCURATE CORRECT ANSWERS

what is chemistry? - correct answers study of the composition, structure, and behavior of matter What are we surrounded by? - correct answers matter What's the role of a chemist? - correct answers studying matter and it's behavior What is the goal of chemistry? - correct answers understand behavioral, energetic, and structural relationships of matter. Scientific Method Steps - correct answers Ask a Question Do Background Research Construct a Hypothesis Test Your Hypothesis by Doing an Experiment Analyze Your Data and Draw a Conclusion Communicate Your Results What are units? - correct answers standardized measures used to express or compare properties of objects or events. SI system - correct answers built in 1960, lays out a universal language of units built upon the metric system. kilogram (kg) - correct answers the basic SI unit of MASS meter (m) - correct answers the base unit of LENGTH in SI second (s) - correct answers SI unit of TIME kelvin (K) - correct answers SI unit for TEMPERATURE What does the SI system allow? - correct answers consistency and clarity of meaning in units across the globe. What does the metric system allow? - correct answers scaling of base units How many meters are in a centimeter? - correct answers 100 How many meters are in a millimeter - correct answers 1000 How many kilometers are in a meter? - correct answers 1000 How many meters are in micrometers? - correct answers 1000000 how many meters in a nanometer? - correct answers Mass - correct answers the amount of matter an object contains Volume - correct answers represents the amount of space and object takes up How are volume of shapes found? - correct answers measuring dimensions and using formulas How are volumes of irregular objects found? - correct answers displacement Any object that contains mass is also going to contain ________ - correct answers matter Matter is going to occupy _________ - correct answers volume Volume and mass both factor into ________ - correct answers density The more mass an object contains per unit volume..... - correct answers the DENSER it is Equation for density - correct answers D=m/v What is the typical unit for density? - correct answers g/mL OR g/cm^3 multiple units can describe the same __________ - correct answers measure what is scientific notation's goal? - correct answers express such a very small or very large numbers in a more practical way. what power does scientific use to represent very small or large numbers in a practical, effective way? - correct answers powers of 10 Anything less than 1 is ___________ - correct answers negative Anything greater than 1 is _________ - correct answers positive Inexact values - correct answers values that are measured, and by definition are uncertain values. (ex. the pencil is 15.2 cm long) Exact values - correct answers are limited to conversion factors, known definitions, and counted values (values we know 100%) (ex. there are 12 cookies in 1 dozen.) significant figures - correct answers define the meaningful digits in the measurement. what do significant figures serve? - correct answers as guidelines and reminders through the collection and manipulation of data that data that we report should only be significant data in the sense that it should be meaningful Rules of Significant Figures - correct answers 1. Non-zero digits are always significant. (#1-9) 2. Any zeros between two significant digits are significant. 3. A final zero or trailing zeros in the decimal portion ONLY are significant. adding and subtracting sig figs - correct answers keep the fewest number of decimal places multiplying and dividing sig figs - correct answers oleast number of sig figs Energy is the ability to do - correct answers to work and produce heat typical units of energy: - correct answers joules (J) kilojoules (kJ) kilocalories (Kcal or Cal) calories (Cal) Conversion factors - correct answers -4184J = 4.184kJ = 1kCal = 1000 Cal Heat is typically measured in - correct answers Joules or kilojoules Joules is named after a well-to-do physicist and brewery manager - correct answers James Joule kinetic and potential energy are both.... - correct answers complementary forms of energy kinetic energy - correct answers energy of motion kinetic energy formula - correct answers KE=1/2mv^2 kinetic energy increases as the mass and velocity - correct answers increases (direct relationship) potential energy - correct answers stored energy (referred to as the energy of position) a prime example of potential energy is - correct answers a match heat - correct answers a form of energy in transit between warmer and colder objects Temperature - correct answers a statistic, & directly related to the average KE temperature goes up and the average KE of a sample of matter goes ____ as well - correct answers up the kelvin scale is always __________ - correct answers positive absolute 0 is - correct answers 0K (lowest possible temp) The Celsius scale is based on what? - correct answers a widely available standard (water), and is set such that zero water is freezing point and 100 is water's boiling point. certain materials are intended to resist changes in temp, and we call these _________ - correct answers insulators other materials we WANT to heat up readily and transmit heat well- we call these ______________ - correct answers conductors specific heat (s) - correct answers the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius specific heat equation - correct answers q = mcΔT what does q stand for? - correct answers heat absorbed what does the m stand for? - correct answers mass of the material what does the s stand for? - correct answers specific heat, changes based on the material being heated or cooled what does the triangle-T stand for? - correct answers change in temperature we take this nutrition in by three basic forms: - correct answers proteins, carbohydrates and fats (provides ENERGY PER GRAM of fat, carbs, or protein) fats - correct answers 9 kcal/g carbs - correct answers 4 kcal/g Protein - correct answers 4 kcal/g Matter can exist in these 3 phases - correct answers solid, liquid and gas solids have - correct answers Definite shape and volume liquids have - correct answers indefinite shape and definite volume gas' have - correct answers indefinite shape and volume solids liquids and gases, we can view as a ________________ - correct answers collection of particles solids, liquids and gases are referred to as _________ - correct answers condensed phases All matter is composed of - correct answers elements from the periodic table Atom - correct answers simplest building block of matter most basic forms of matter are: - correct answers atoms, molecules and compounds Mixtures - correct answers two or more substances retains it's individual identity homogeneous mixture - correct answers A mixture in which substances are evenly distributed throughout the mixture (example milk) Hetergeneous Mixture - correct answers A mixture that is not uniform, in which different samples may have different compositions (ex: fruit salad, trail mix) the properties of matter can be divided into both _______ & _________ properties - correct answers extensive and intensive intensive property - correct answers a property that depends on the type of matter in a sample, not the amount of matter (ex. density) extensive property - correct answers depends on sample size examples of extensive properties - correct answers mass, length, volume examples of intensive properties - correct answers density, boiling point, color physical property - correct answers a quality or condition of a substance that can be observed or measured without changing the substance's composition chemical properties - correct answers Characteristic that cannot be observed without altering the substance phase changes are ________ between the 3 different states of matter: solid, liquid and gas - correct answers TRANSITIONS six different possibilities of phases changes between solids, liquids and gases. - correct answers 1. Freezing (liquid to solid) 2. Sublimation (solid to gas) 3. Condensation (gas to solid) 4. Melting (solid to liquid) 5. Deposition (gas to solid) 6. Vaporization (liquid to gas) Democritus (400 BC) - correct answers Greek philosopher who coined the term "atoms", said shapes of atoms were related to properties Dalton (1805) - correct answers referred to as father of atomic theory suggested the billiard ball model Assumptions of Dalton's Atomic Theory - correct answers 1. elements are made of extremely small particles called atoms, and atoms of a given element are identical (in size, mass and other properties) 2. atoms cannot be subdivided, created or destroyed 3. atoms of different elements combine in simple whole number ratios to form chemical compounds 4. in chemical reactions, atoms are combined, separated, or rearranged. J.J. Thomson (1897) - correct answers -discovered negative particles in atoms called electrons -"plum pudding"(1904) model_electrons (negatively charged subatomic particles) are scattered about the atom like plums in a plum pudding. - the "pudding" part of the atom was composed of positively charged material Rutherford (1911) - correct answers thompson's student is credited w/ discovery of the positively charged nucleus of the atom Rutherford's Planetary Model - correct answers -set up a "planetary" model based on all the information we have so far. -the center of the atom, the nucleus, acted much like our sun -the problem w/ the model is that physics says that the electrons in this model aren't stable in their orbits and would eventually spiral in the nucleus Niels Bohr (1913) - correct answers -addressed the instability of the Rutherford model -the bohr model has a similar "planetary orbit" look but requires electrons to exist in stable stationary orbit set at certain distances from their nucleus -works well for explaining behavior of H or He, but breaks down for atoms w/ more than one electron what did the bohr model help explain? - correct answers the absorption and emission of light by the hydrogen atom who discovered the proton in 1920? - correct answers rutherford The proton is the __________ charged particle in the nucleus - correct answers positively experimentally, protons were shown to be ____________ of other nuclei - correct answers building blocks how did rutherford show that protons were shown to be building blocks of other nuclei? - correct answers colliding alpha particles w/ different gases and finding that protons could be ejected by the collisions who developed the Schrodinger equation? - correct answers Schrodinger what does the Schrodinger model replace? - correct answers replaces planetary orbits w/ atomic orbits atomic orbits define __________ around the atom which are __________ of holding up to _____ electrons each - correct answers 3D shapes, capable, 2 Our modern view of the atom - correct answers -dense (positive) center (nucleus) -P+N in the nucleus -tiny electrons in atomic orbitals groups 1 and 2 (alkali metals- Li, Na, K, Rb, Cs and alkaline earth metals- Mg, Ca, Sr, Ba, Ra) - correct answers -metals are generally GOOD CONDUCTORS of heat and electricity. -both react with water but AM are vigorous (and mores going down the column) -soft and shiny (sodium, Na, will cut w/ a butter knife) groups 17 and 18 (halog