Chemistry Mid-Term

Front 1

which of the following is not a type of qualitative data

Back 1

mass

Front 2

what is a scientific hypothesis

Back 2

a simple, testable statement of a prediction based on available information

Front 3

which of the following is the most important contribution made to modern chemistry by alchemists

Back 3

experimental approach

Front 4

who discovered the element oxygen

Back 4

priestly

Front 5

which branch of chemistry primarily studies compounds containing carbon

Back 5

organic chemistry

Front 6

t/f
the scientific method involves following a rigidly defined series of steps to arrive at a solution

Back 6

false

Front 7

t/f
everything in the material universe is composed of chemicals

Back 7

true

Front 8

first proposed that elements are substances that cannot be chemically decomposed into simpler substances

Back 8

robert boyle

Front 9

proposed the term atom and believed it to be the basic building block of all matter

Back 9

democritus

Front 10

accidentally synthesized urea from two inorganic compounds, leading to the rise of organic chemistry

Back 10

friedrich wohler

Front 11

how many atoms of oxygen are there in five molecules of penicillin G(C17H20O4S)

Back 11

20

Front 12

the freezing point of nitrogen is -210 celsius. what would that temperature be in kelvins

Back 12

63 K

Front 13

the amt of energy required to raise the temperature of 1 gram of water 1 degree celsius is defined as a

Back 13

calorie not Calorie

Front 14

in the chemical formula 10Al(C2H3O2)3 the numeral 10 is a

Back 14

coefficient

Front 15

t/f
the joule is the standard SI unit of measurement for energy

Back 15

true

Front 16

t/f
the second character in an elements symbol is always lowercase

Back 16

true

Front 17

t/f
temp measures the total kinetic energy in a sample

Back 17

false

Front 18

t/f
Reactions that absorb energy are exothermic

Back 18

false

Front 19

poor conductor of electricity

Back 19

physical property

Front 20

reacts violently with water

Back 20

chemical property

Front 21

freezes at 2115 degrees celsius

Back 21

physical property

Front 22

sinks in water

Back 22

physical property

Front 23

as entropy __________, the randomness in a system increases

Back 23

increases

Front 24

the SI unit that represents the amt of particles of a substance is a

Back 24

mole

Front 25

what volume does a 1carat (.2g )diamond occupy (density=3.27g/ml)

Back 25

0.06 ml

Front 26

the measurement 0.037010 has how many sig figs

Back 26

5

Front 27

a fraction equal to one that contains both the original unit and its equivalent value in a new unit is called a

Back 27

conversion factor

Front 28

what indicates the precision of an instrument and helps scientists report measurements honestly

Back 28

significant digit

Front 29

t/f
when determining sig digs in multiplication and division problems, the answer cannot contain more sig digs than the measurement with the least number of sig digs

Back 29

true

Front 30

t/f
the unit for volume is derived from the SI unit for length, meter

Back 30

true

Front 31

find the volume in mL, occupied by 454g of copper, which has a density 8.92g/mL

Back 31

50.90mL

Front 32

who was the first to refer to the smallest particles composing matter as atoms

Back 32

democritus

Front 33

the type of sub-level found in all principle energy levels is the ____ sub-level

Back 33

s

Front 34

which is the correct electron configurations for aluminum atomic number 13

Back 34

1s2 2s2 2p6 3s2 3p1

Front 35

tritium is an isotope of hydrogen that has a mass number of 3 what is its isotopic notation

Back 35

3
H
1

Front 36

how many neutrons does the isotope
125
Te
52
have

Back 36

73

Front 37

the maximum number of electrons that can be found in any atoms second principle energy level is

Back 37

8

Front 38

two different isotopes of a single element would have the same number of _______ but a different number of ______

Back 38

protons / neutrons

Front 39

t/f
the general region of space where an electron is most probably found is known as an orbital

Back 39

true

Front 40

t/f
an electron can behave as either a wave or a particle

Back 40

true

Front 41

t/f
an atom that gains three electrons will have a +3 charge

Back 41

false

Front 42

t/f
the first quantum number identifies the principle energy level of an electron

Back 42

true

Front 43

first experimental atomic model

Back 43

john dalton

Front 44

cathode rays

Back 44

jj thomson

Front 45

neutrons

Back 45

james chadwick

Front 46

planetary model of the atom

Back 46

niels bohr

Front 47

which had the least mass-a electron, proton or a neutron

Back 47

electron

Front 48

mass number = number of ___________ + # of _______

Back 48

protons and neutrons

Front 49

________ is determined by the weighted average of isotopes of an element

Back 49

atomic mass

Front 50

the electrons in the outermost energy level that are important in bonding are called _______

Back 50

valence electrons

Front 51

whose work resulted in the revision of the periodic law and the atomic number being used as the organizing factor for the elements of the periodic table

Back 51

moseley

Front 52

the nobel prize winning chemist devised an electronegativity scale

Back 52

pauling

Front 53

mendeleev's periodic table arranged elements by

Back 53

atomic mass

Front 54

it is the lightest and most abundant element in the universe, is extremely flammable in air and is used in the industrial production of ammonia

Back 54

hydrogen

Front 55

existing as diatomic molecules this gas is tasteless colorless and odorless and it accounts for approx. 78 % of the earth's atmosphere

Back 55

nitrogen

Front 56

what is the large group of elements that have their highest energy electrons in the interior d sub-level

Back 56

transition metals

Front 57

t/f
high electronegativities are associated with large ionization energies and high electron affinities

Back 57

true

Front 58

t/f
graphite and diamond are both composed of the same element carbon

Back 58

true

Front 59

t/f
none of the noble gases form compounds with other elements

Back 59

false

Front 60

halogens are easily obtainable in their elemental forms

Back 60

false

Front 61

what name is given to the horizontal rows in the periodic table

Back 61

periods or series

Front 62

why do elements in the same family have similar physical and chemical properties

Back 62

same number of valence electrons

Front 63

which element is the most electronegative as well as the most reactive

Back 63

Fluorine

Front 64

what type of bond would you expect in a compound of oxygen and sodium

Back 64

ionic bond

Front 65

an orderly arrangement of ions in a three-dimensional pattern within a compound is called a...

Back 65

crystal lattice

Front 66

a dash in a lewis structure represents

Back 66

two electrons

Front 67

the central atom in a lewis structure is usually the atom

Back 67

with the most unpaired electrons

Front 68

t/f
when drawing lewis structures some atoms may need to share more than one electron pair with another atom in order to satisfy the octet rule

Back 68

true

Front 69

t/f
atoms with fewer than 4 valence electrons tend to gain electrons when bonding

Back 69

false

Front 70

t/f
the greater the difference in electronegativity between two elements is the greater the polarity of the resulting molecule

Back 70

true

Front 71

t/f
when atoms bond they will seek a higher more stable energy state

Back 71

false

Front 72

chemical bonds between atoms involve the rearranging of ______ to maximize stability

Back 72

electrons

Front 73

the ratio of cations to anions in an ionic compound is expressed in a chemical formula known as a ______

Back 73

formula unit

Front 74

what type of bond forms as a result of orbitals overlapping end to end

Back 74

sigma

Front 75

how many sigma and pi bonds are there in a molecule of N2

Back 75

a sigma and two pi bonds

Front 76

which of the following shapes is always polar

Back 76

bent (109.5 degrees)

Front 77

what is the shape of a molecule that has four electron concentrations but only three of them are occupied by bonding pairs of electrons

Back 77

pyramidal

Front 78

t/f
a sigma bond is stronger than a pi bond

Back 78

true

Front 79

t/f
a sigma bond can form from the overlap of either s or p orbitals

Back 79

true

Front 80

t/f
because of its high electronegativity a molecule of fluorine is polar

Back 80

false

Front 81

the assumption that molecular shapes are largely determined by the repulsion of regions of electron concentration is known as the _________________ theory

Back 81

valence shell electron pair repulsion (VSEPR)