Unit 2 - bonding

Question 1

what is bonding?

Answer 1

-the joining of 2 atoms in a stable arrangement

Question 2

what happens during bonding?

Answer 2

-elements will gain, share or lose electrons to reach electron configuration of the noble gas closest to them in the periodic table

Question 3

describe ionic bonds

Answer 3

-the transfer of electrons from one element to another

Question 4

describe covalent compounds

Answer 4

-the sharing of electrons between two atoms

Question 5

what is a molecule?

Answer 5

-compound or element containing 2+ atoms joined

Question 6

what are ions

Answer 6

-charged atoms
-# of protons & electrons in the atom is unequal = not neutral

Question 7

describe covalent compounds

Answer 7

-two nonmetals combine
-or a metalloid bonds to a nonmetal

Question 8

describe ionic compounds

Answer 8

-consist of oppositely charged ions that have strong electrostatic attraction for each other
-always*** formed from metal & nonmetal

Question 9

what are the two types of ions?

Answer 9

-cations
-anions

Question 10

describe cations

Answer 10

-positively charged ions
-has fewer electrons than protons
-by losing 1-3 electrons, an atom forms a cation w/ a completely filled outer shell of electrons
-metals like Na & Mg form cations

Question 11

describe anions

Answer 11

-negatively charged ions
-more electrons than protons
-by gaining 1-3 electrons, an atom forms an anion w/ a completely filled outer shell of electrons
-nonmetals like Cl form anions

Question 12

what is the octet rule?

Answer 12

-main group element is especially stable when it possesses an octet (8) of electrons in its outer shell
-will become the electron configuration of the nearest noble gas

Question 13

common ions found in the human body

Answer 13

-Ca2+ = bones
-Na+ and K+ = body fluids
-Fe2+ = hemoglobin of the blood
-Cl1- = gastric juices of the stomach & other fluids
-Mg2+ = needed for nerve transmission & muscle control

Question 14

how to you name ions? give examples

Answer 14

-add suffix ‘ide’
-ex: oxide, sulfide

Question 15

what must be included when naming compounds w/ transition metals?

Answer 15

include the roman numerals that show which charge of the transition metal is being used

Question 16

describe the physical properties of ionic compounds

Answer 16

-crystalline solids
-very high melting & boiling points
-when dissolved in water, they separate into cations & anions = increased conductivity of the solution

Question 17

what is a polyatomic ion?

Answer 17

-cation or anion that contains more than one atom

Question 18

what is the only known polyatomic cation?

Answer 18

ammonium (NH4+)

Question 19

carbonate molecular formula

Answer 19

CO3(2-)

Question 20

hydrogen carbonate molecular formula

Answer 20

HCO3 (-)

Question 21

acetate molecular formula

Answer 21

CH3CO2 (-)

Question 22

cyanide molecular formula

Answer 22

CN(-)

Question 23

nitrate molecular formula

Answer 23

NO3(-)

Question 24

nitrite molecular formula

Answer 24

NO2(-)

Question 25

hydroxide molecular formula

Answer 25

OH(-)

Question 26

phosphate molecular formula

Answer 26

PO4(3-)

Question 27

sulfate molecular formula

Answer 27

SO4(2-)

Question 28

sulfite molecular formula

Answer 28

SO3(2-)

Question 29

what is a molecule

Answer 29

-a covalent compound
-discrete group of atoms held together by covalent bonds

Question 30

what are unshared e- pairs?

Answer 30

lone pairs, they are unbonded

Question 31

what does the lewis structure show?

Answer 31

-shows location of valence electrons

Question 32

how many bonds will H form?

Answer 32

1

Question 33

how many bonds will C form?

Answer 33

4

Question 34

how many bonds will N form? & how many lone pairs will it have

Answer 34

3 bonds
1 lone pair

Question 35

how many bonds will O form & how many lone pairs will it have

Answer 35

2 bonds
2 lone pairs

Question 36

how many bonds will halogen form & how many lone pairs will it have?

Answer 36

1 bond
3 lone pairs

Question 37

all amino acids are:

Answer 37

covalent compounds

Question 38

Lewis structure for polyatomic ions:

Answer 38

-add one electron for each negative charge
-subtract one electron for each positive charge

Question 39

what is resonance?

Answer 39

-delocalization of electrons
-same arrangement of atoms, different arrangement of electrons

Question 40

what does delocalization do?

Answer 40

-makes a molecule stable

Question 41

naming covalent compounds prefixes

Answer 41

-mono
-di
-tri
-tetra
-penta
-hexa
-hepta
-octa
-nona
-deca

Question 42

what is valence shell electron pair repulsion theory?

Answer 42

either an atom or a lone pair is a group that surrounds an atom

Question 43

linear molecular shape group & bond angle

Answer 43

-2 groups
-180 degree bond angle
-ex: CO2

Question 44

trigonal planar molecular shape group & bond angle

Answer 44

-3groups
-120 degree bond angle
-ex: BF3 & H2CO (formaldehyde)

Question 45

tetrahedral molecular shape group & bond angle

Answer 45

-4 groups
-109.5 bond angle
-ex: CH4 (methane)

Question 46

trigonal pyramid molecular shape group & bond angle

Answer 46

-4 groups + 1 lone pair
-107 degree bond angle
-ex: NH3 (ammonia)

Question 47

bent shape molecular shape group & bond angle

Answer 47

-4 groups + 2 lone pairs
-105 degree bond angle
-ex: H2O

Question 48

what is electronegativity

Answer 48

-the measure of an atom’s attraction for electrons in a bond
-not a complete transfer of electrons == SLIGHTLY negative charges

Question 49

difference between ionization & electronegativity ?

Answer 49

-ionization is the complete transfer of electrons (formation of anions)

Question 50

how does electronegativity change across the periodic table?

Answer 50

-across the period = increases
-down the group = decreases

Question 51

Electronegativity difference:

Answer 51

-0.5 = nonpolar
-0.5-1.9 = polar covalent
-greater than 1.9 = ionic