CHEM 109 EXAM 1 PRACTICE EXAM MULTIPLE Choices Questions And Answers

is the study of matter and the changes that matter undergoes. - correct answers chemistry is anything that has mass and occupies space. - correct answers Matter is a form of matter that has definite composition and distinct properties - correct answers substance substances can be either ____ or ____ - correct answers elements or compounds a substance that cannot be separated into simpler substances by chemical means. - correct answers element contains 2 or more different atoms - correct answers molecule fundamental particle that retains the identity of the elements - correct answers atom substance made of 2 or more different types of atoms - correct answers compound rows of periodic table - correct answers periods columns of periodic table - correct answers groups diatomic substances - correct answers Br I N Cl H O F element may consist of __ or __ - correct answers atoms or molecules types of matter - correct answers liquid gas plasma solid condensed and crystalline - correct answers solid doesnt flow,def volume, def shape - correct answers solid vibration - correct answers solid, liquid limited translation and rotation movement - correct answers liquid arranged in 3D - correct answers condensed particles of matter are as close as possible - correct answers crystalline held tightly but vibrating in place - correct answers vibration somersaults - correct answers rotation point A to point B, straight line - correct answers translation not limited translation and rotation - correct answers gases compressable and flow easily - correct answers gases a physical combination of two or more substances. - correct answers mixture uniform throughout. - correct answers homogeneous mixture not uniform throughout - correct answers heterogeneous mixture is one a substance exhibits as it interacts with another substance. - correct answers chemical property is one that results in a change of composition; the original substances no longer exist. - correct answers chemical change chemical change ex - correct answers digestion, combustion, oxidation chemical property ex - correct answers flammability, corrosiveness changes of state - correct answers physical change physical property - correct answers color, melting point, boiling point is one that can be observed and measured without changing the identity of the substance. - correct answers physical property is one in which the sate of matter changes, but the identity of the matter does not change. - correct answers physical change revised metric system designed for universal use by scientists - correct answers international system of units name the system of units - correct answers length (m), mass (kg), time (s), electric current (A), temp (K), amount (mol) numbers that have defined values - correct answers exact numbers obtained by any method other than counting - correct answers inexact meaningful digits in a reported number - correct answers sig figs the last digit in a measured number - correct answers uncertain digit tells us how close a measurement is to the true value - correct answers accuracy tells us how closely multiple measurements of the same thing are to one another - correct answers precision is a fraction in which the same quantity is expressed one way in the numerator and another way in the denominator - correct answers conversion factor the ratio of mass to volume - correct answers density depends on the amount of matter - correct answers extensive property does not depend on the amount of matter - correct answers intensive property examples of extensive properties - correct answers mass, volume, energy examples of intensive properties - correct answers temperature, density zeros to the left of the first nonzero are _____ - correct answers not significant zeros to the right of the last nonzero digit are ______ - correct answers are sig if there is a decimal (9.550) zeros to the right of the last non zero digit that doesn't have a decimal ____ - correct answers may or may not be sig (1200) in addition and subtraction explain sig figs - correct answers the answer should have the sig figs of the number with the least decimal places (102.50 + .231 = 102.73) in multiplication and division explain sig figs - correct answers determined by the original number that has least number of sig figs explain the parts of john dalton's atomic theory - correct answers 1) elements are made of small particles called atoms 2) all atoms of a given element are identical and different from other elements 3) compounds are more than one element and in any compound the same types of atoms are present in the same numbers 4) a chemical reaction rearranges atoms in chemical compounds; does not create or destroy dif samples of a given compound always contain the same elements in the same mass ratio - correct answers law of definite proportions if two elements can combine to form more than one compound with each other, the masses of one element that combine with a fixed mass of the other element are in ratios of small whole numbers - correct answers law of multiple proportions negatively charged plate - correct answers cathode when metal plates are connected to a high-voltage source the cathode ______ - correct answers emits an invisible ray the cathode ray is drawn to the ____ - correct answers anode particles that are negatively charged - correct answers electrons cathode rays may be deflected by _______ - correct answers magnetic or electric person who determined thee charge to mass ratio of an electron - correct answers J.J. Thomson person who measured the charge of an electron with great precision - correct answers R.A. Millikan three types of decay particles produced by radioactive decay - correct answers alpha, beta, gamma person who used alpha particles to prove there is a nucleus - correct answers ernest rutherford ernest rutherford is known for - correct answers gold foil experiment where most particles when through, but some bounced at weird angles accounts for most of an atom's mass and is an extremely dense central core within the atom - correct answers nucleus positively charged particles found in the nucleus. - correct answers protons electronically neutral particles found in the nucleus. - correct answers neutrons the number of protons in nucleus - correct answers atomic number (at bottom and then at top on periodic table) the total number of protons and neutrons - correct answers mass number (top) atoms that have the same atomic number but different mass numbers. - correct answers isotopes good conductors of heat and electricity - correct answers metals poor conductors of heat or electricity - correct answers nonmetals have intermediate properties btwn metal and nonmetal - correct answers metalloids the most direct way to measure molecular mass - correct answers mass spectrometer on periodic table, represents the average mass of the naturally occurring mixture of isotopes - correct answers atomic weight the percentage of each isotopes that's present in a natural sample - correct answers natural abundance aka relative abundance the natural or relative abundance in percent converted back to fraction - correct answers fractional abundance (divide by 100) cluster of atoms that are held together with covalent bonds but happen to have one more electron than they're expected to have - correct answers polyatomic molecules between two non metals, form because they share electrons - correct answers covalent compounds between metals, form becuase they transfer electrons - correct answers ionic compounds denotes the composition of the substance (H2O) - correct answers chemical formula shows the exact number of atoms of each element in a molecule (H:O:H) - correct answers molecular formula shows not only the elemental composition, but also the general arrangements (H-O-H) - correct answers structural formula the mass in atomic mass units of an individual molecule - correct answers molecular mass to calculate molecular mass - correct answers (atomic mass for each element in molecule)x(number of atoms of the element) and then total the masses the amount of a substance that contains as many elementary entities as there are atoms in exactly 12 g of carbon-12 - correct answers mole avogadro's number - correct answers 6.022 x 10^23 the mass in grams of 1 mole of the substance - correct answers molar mass (g/mol) particles used with avogadro's number - correct answers units, atoms, molecules substances that consist of just two different elements - correct answers binary molecular compounds between two non-metals list off the prefixes - correct answers mono- 1 di-2 tri - 3 tetra- 4 penta - 5 hexa - 6 hepta - 7 octa - 8 nona - 9 deca - 10 a substance that produces hydrogen ions when dissolved in water - correct answers acid to name acids - correct answers drop the -gen change the -ide ending on second element to -ic consists of just one atom with a positive or negative charge - correct answers atomic or monatomic ion the loss of one or more electrons from an atom yields a ____ - correct answers cation (positive charge) an ion whose charge is negative due to an increase in the number of electrons - correct answers anion polyatomic anions that contain one or more oxygen atoms and one atom of another element - correct answers oxoanions acids that contain oxoanions - correct answers oxoacids an acid based on the -ate ion is called ___ - correct answers -ic acid an acid based on the -ite ion is called ____ - correct answers -ous acid compounds that have a specific number of water molecules within their solid structure - correct answers hydrates gives the simplest ratio of elements in a compound - correct answers empirical formula a list of the percent by mass of each element in a compound - correct answers percent composition percent composition by mass formula - correct answers n x atomic mass of element / molecular mass of compound x 100 n = number of atoms uses chemical symbols to denote what occurs in a chemical reaction - correct answers chemical equation the reactant used up first in a reaction - correct answers limiting reactant those present in quantities greater than necessary to react with the quantity of limiting reactant - correct answers excess reactants the amount of product that forms when all the limiting reacts to form the desired product - correct answers theoretical yield the amount of product actually obtained from a reaction - correct answers actual yield tells what percentage the actual yield is of the theoretical yield - correct answers percent yield formula for % yield - correct answers % yeild = actual yield / theoretical yield x 100 the experimental determination of an empirical formula is carried out by a - correct answers combustion analysis conversion for kelvin - correct answers k = C + 273.15