Chapter 6: Relationships and Patterns in Chemistry

Question 1

who came up with the idea of conservation of mass?

Answer 1

Antoine Laurent de Lavoisier

Question 2

who said this: “Nothing is lost, nothing is created, everything is transformed”

Answer 2

Antoine Laurent de Lavoisier

Question 3

Johann Döbereiner realized he could organize certain elements into groups of _____ which he called ______

Answer 3

three called triads

Question 4

Antoine Émile Béguyer de Chancourtois was the first to recognize the ________ of elements

Answer 4

periodicity

Question 5

in what order did Chancourtois organize the elements?

Answer 5

by atomic weight

Question 6

Julius Lothar Meyer published the periodic table based on the _______ of each element?

Answer 6

valency

Question 7

John Newlands noticed that some trends were based of off which number? What was the name of this law?

Answer 7

8

law of octaves

Question 8

Dimitry Mendeleev ordered the periodic table by _______?

Answer 8

molar mass

Question 9

T or F: Mendeleev left empty spots in his table?

Answer 9

True, he predicted undiscovered elements that would take those places

Question 10

def: arranging the elements by increasing aotmic mass produced an observable patter in which similar properties repeat on a regular basis, or periodically

Answer 10

periodic law

Question 11

what were two problems with Mendeleev’s table?

Answer 11

1. it didn’t predict the noble gases (they don’t react so it’s hard to discover them)
2. it couldn’t locate hydrogen, as it fit in multiple places

Question 12

who reordered the periodic table based on atomic number?

Answer 12

Henry Moseley

Question 13

what are the elements 93-118 called?

Answer 13

the trans-uranium elements

Question 14

def: horizontal rows on the periodic table, where atomic number increases by one and properties gradually change from one end to the other

Answer 14

periods

Question 15

def: vertical columns on the periodic table, in which elements have similar properties, owing to the similarity of their electron configurations

Answer 15

groups (families)

Question 16

def: groups 1 & 2 (s block) and 13-18 (p-block) on the periodic table, except hydrogen

Answer 16

main group elements

Question 17

def: groups 3-12 on the periodic table, encompassing all the metals of the d and f blocks

Answer 17

transition metals

Question 18

def: two rows of elements generally placed below the main table, comprising the metals of the f block

Answer 18

inner transition metals

Question 19

def: elements Z = 57 through Z = 71, lanthanum through lutetium

Answer 19

lanthanides

Question 20

def: elements Z = 89 through Z = 103, actinium through lawrencium

Answer 20

actinides

Question 21

def: any of an atom’s electrons that can participate in bond formation with other atoms, whether ionically or covalently

Answer 21

valence electron

Question 22

for transition metals, valence electrons are all those _______ the ________, regardless of their principal quantum number

Answer 22

outside the atom’s noble gas core

Question 23

def: any of an atom’s electrons that isn’t a valence electron and that doesn’t participate in bond formation

Answer 23

core electron

Question 24

def: the metallic elements of the periodic table that fall between the transition metals and the metalloids

Answer 24

post-transition metals

Question 25

def: predictable and regular patterns of cyclical change in elemental properties throughout the periodic table, moving either vertically or horizontally

Answer 25

periodic trends

Question 26

def: an expression of the size of an atom, representing the typical distance from the centre of it's nucleus to the boundary of its electron cloud

Answer 26

atomic radius

Question 27

why can't we determine the precise size of an atom?

Answer 27

because the electron cloud does not have distinct boundaries

Question 28

def: an estimate of the size of an atom, based on half the distance between covalently bonded atoms

Answer 28

covalent radius

Question 29

def: an estimate of the size of a metal atom, based on half the distance between the nuclei and adjacent atoms in a metal lattice

Answer 29

metallic radius

Question 30

what two factors influence the size of an atom's electron cloud?

Answer 30

- how many energy shells contain electrons | - the amount, nature and separation of charge within the atom

Question 31

as the principle quantum number goes up, the number of outermost shells _____ and they get _____ in distance to the nucleus

Answer 31

goes up and they get further away

Question 32

what force are neutrons held together by?

Answer 32

residual strong force

Question 33

T or F: adding more electrons and protons increases the amount of opposite charge in the atom, increasing the nucleus's inward pull on the valence electrons, making atoms smaller across the table

Answer 33

True

Question 34

def: the repulsive action of inner core electrons on outer valence electrons, effectively reducing the nucleus's inward pull, causing the atom to increase in size

Answer 34

shielding effect

Question 35

def: the net positive charge experienced by an electron in a multi-electron atom, representing less than the full nuclear charge as inner electrons repel outer electrons, offsetting some of the nucleus's inward pull

Answer 35

effective nuclear charge (Zeff)

Question 36

when metals form cations, what happens to their ionic size?

Answer 36

it's smaller than it's atomic radius

Question 37

when non-metals form anions, what happens to their ionic size?

Answer 37

it's larger than it's atomic radius

Question 38

def: the amount of energy required to remove the most loosely held electron from a gaseous atom to form a cation to increase its positive charge

Answer 38

ionization energy (IE)

Question 39

generally speaking, each electron is ____ to remove than the last

Answer 39

harder

Question 40

as Zeff increases, atoms become ______ and electrons become more ____ to remove, causing an ________ in ionization energy

Answer 40

atoms become smaller and electrons become more difficult to remove, causing an increase in ionization energy

Question 41

def: a chemical property that describes an atom's (or a group of atoms') ability to attract electrons towards itself

Answer 41

electronegativity (EN)

Question 42

def: the change in energy when an atom gains an electron to form an anion, or when an anion gains another electron, increasing its negative charge

Answer 42

electron affinity

Question 43

the stronger an element attracts electrons, the _____ energy it releases when gaining an electron, making its electron affinity ______

Answer 43

the more energy releases when gaining an electron, making its electron affinity greater

Question 44

def: a numerical value representing the difference in the electronegativities of two atoms

Answer 44

ΔEN

Question 45

metals have relatively _____ ionization energies

Answer 45

low

Question 46

non-metals have relatively _____ electronegativities

Answer 46

high

Question 47

non-metals have relatively _____ electron affinities

Answer 47

high

Question 48

an ionic bond will form between a metal and a non metal if their ΔEN is greater than _____

Answer 48

1.7

Question 49

a covalent bond will form between two non-metals if their ΔEN value is less than _______

Answer 49

1.7

Question 50

def: a covalent bond between non metal atoms with the same electronegativities, where electron sharing is equal

Answer 50

non polar covalent bond

Question 51

a non polar covalent bond forms between two non-metals if their ΔEN value between ____ and _____

Answer 51

0 and ~ 0.4

Question 52

def: a covalent bond between two non-metals in which electron sharing is sufficiently unequal that the bond displays significant and meaningful ionic nature

Answer 52

polar covalent bond

Question 53

def: the non-integer charge values at the ends of a polar covalent bond, due to the uneven distribution of electron density within the bond

Answer 53

partial ionic charges

Question 54

def: a simplified diagram that communicates molecular structure using element's symbol as well as dots and lines

Answer 54

Lewis Structure

Question 55

which two noble gases form compounds?

Answer 55

xenon and krypton

Question 56

def: describes an atom's combining power, often in terms of how many hydrogen atoms it can covalently bond with, or how many chloride anions it can ionically bond with

Answer 56

valency

Question 57

rather than lattices, covalent compounds form______

Answer 57

separate and distinct molecules

Question 58

def: any pair of valence electrons that are nonbonding, as atoms don't share them with other atoms

Answer 58

lone pair

Question 59

T or F: Lone pairs may form or disperse because of bond formation

Answer 59

True

Question 60

def: an observational rule in chemistry that says the valence shells of the first-period elements hydrogen and helium can hold a maximum of two electrons, never more

Answer 60

duet rule

Question 61

which atoms do not obey or exceed the octet rule?

Answer 61

H, He, Be, B, Al

Question 62

def: an observational rule of thumb in chemistry that says main-group elements from periods 2 to 7 seek to have eight electrons in their valence shell

Answer 62

octet rule

Question 63

T or F: the central atom in a binary compound is usually the one of lower electronegativity

Answer 63

True

Question 64

def: covalent bonding between two atoms who share more than two electrons

Answer 64

multiple bonds

Question 65

def: a configuration of elements from periods 3 to 7, in which their valence shells expand past eight electrons as the central atom, as they can incorporate d orbitals

Answer 65

expanded octet

Question 66

def: different, but equivalent Lewis structures of the same molecule, showing all the possible double bond locations, connected by a double headed arrow

Answer 66

resonance structures

Question 67

def: electrons in a molecule, ion or solid metal that aren't associated with a single atom or covalent bond, allowing them to be covalent to more than two atoms

Answer 67

delocalized electrons

Question 68

electron delocalization allows the creation of an _________

Answer 68

electrical current

Question 69

def: a model chemists use to predict a molecule's geometry based on how many groups of electrons surround the central atom, both bonding electrons and lone pairs

Answer 69

valence shell electron pair repulsion theory | VSEPR

Question 70

def: a number used in VSEPR theory to predict molecular geometry, that is equal to the number of peripheral atoms plus the number of lone pairs

Answer 70

steric number

Question 71

how do you find the steric number?

Answer 71

peripheral atoms + lone pairs = steric number

Question 72

def: the superposition or mixing of atomic orbital wave functions to produce new hybrid orbitals with unique shape and energies

Answer 72

orbital hybridization

Question 73

def: the strongest type of covalent bond, formed between two atoms when their orbitals overlap head on

Answer 73

sigma bond

Question 74

def: a second type of covalent bond that is weaker than a sigma bond, formed between two atoms when their p orbitals are parallel and overlap side on

Answer 74

pi bond

Question 75

def: a vector quantity that expresses a bond's polarity, showing the separation of opposing charges, and the directionality of that separation (a moment)

Answer 75

bond dipole moment

Question 76

T or F: A polar bond has a relatively large ΔEN value, producing a bond dipole moment that is not strong enough to affect behaviour, while a non-polar bond’s ΔEN value produces one that is

Answer 76

False

Question 77

def: a molecule that has an overall, or net dipole moment, because of it's bond polarities and its molecular geometry

Answer 77

polar molecule

Question 78

T or F: Polar molecules must contain polar bonds, but cannot be symmetrical, in both structure and composition – polar bonds and asymmetrical structure or composition make polar molecules

Answer 78

True

Question 79

def: the attractive force that exists between the partial positive charge of one polar molecule and the partial negative charge of another

Answer 79

dipole-dipole force

Question 80

def: an electrostatic attraction that forms between the partially positive hydrogen in a highly polarized bond (usually H-N, H-O, and H-F) and the negative lone pair on a nearby atom

Answer 80

hydrogen bond

Question 81

def: a weakly attractive force that forms when non polar molecules gain temporary dipole moments

Answer 81

London dispersion forces