Gen chem 1 and 3

Question 1

What are the four exceptions to the octet rule for an incomplete octet and how many valence electrons they have?

Answer 1

Hydrogen= 2 
Lithium= 2 
Beryllium= 4
Boron= 6

Question 2

How many valence electrons can the elements in period 3 and greater hold?

Answer 2

These elements can hold six valence electrons.

Question 3

What are three specific elements that can hold more than eight electrons and what type of octet is this called?

Answer 3

This is called an expanded octet
phosphorus= 10
sulfur= 12
chlorine= 14

Question 4

What do nonmetals and metals do to form an octet?

Answer 4

Nonmetals gain electrons and metals lose electrons

Question 5

Describe an ionic bond in terms of electron transfer?

Answer 5

electrons from an atom with a low ionization energy, typically a metal, are transferred to an atom with a high electron affinity, typically a nonmetal

Question 6

what holds ions together(what force)?`

Answer 6

Ionic bonds are held together by electrostatic attraction (force between opposite charges)

Question 7

in covalent bonds, what do the atoms in the bond have in common?

Answer 7

they have similar electronegativities

Question 8

what is a nonpolar covalent bond?

Answer 8

it is when atoms in a bond share electrons equally

Question 9

what is a polar covalent bond?

Answer 9

it is when atoms in a bond don’t share electrons equally

Question 10

what is a coordinate covalent bond?

Answer 10

it is when one atom contributes both electrons for the bond

Question 11

in ionic bonds, how do the atoms in the bond differ?

what must the elecneg value difference be according to the pauling scale?

Answer 11

they have different electronegativities

the pauling elecneg difference has to be 1.7 or greater

Question 12

why do ionic bonds have such high melting and boiling points?

Answer 12

these are high because of the strength of the electrostatic force

Question 13

what kind of melting and boiling points do covalent compounds have and are they good conductors of electricity

Answer 13

they are low and not good conductors

Question 14

what type of bond is the longest?

Answer 14

sigma bond

Question 15

define bond energy

Answer 15

bond energy is the energy required to break a bond by separating its components into their isolated, gas atomic states.

Question 16

why does polarity occur

Answer 16

polarity is the electronegative difference between atoms

Question 17

what is the elecneg difference on the pauling scale for nonpolar bonds

Answer 17

it is less than 0.5

Question 18

what is the elecneg difference on the pauling scale for polar covalent bonds

Answer 18

the difference is between 0.5 and 1.7

Question 19

what is the dipole moment equation and what does each thing stand for?

Answer 19

p=qd
p is a dipole moment
q is the magnitude of the charge
d is the displacement vector between the two charges

Question 20

describe the electron attack in the coordinate covalent bond

what type of reactions contain coordinate covalent bonds?

Answer 20

A LONE PAIR FROM ONE ATOM ATTACKED ANOTHER ATOM WITH AN UNHYBRIDIZED P ORBITAL
they are in lewis acid base acid base reactions

Question 21

define a lewis acid

define a lewis base

Answer 21

lewis acids can accept a lone pair of electrons

lewis bases donate a pair of electrons

Question 22

how do you determine the best lewis structure for a compound if there is more than one?

Answer 22

the most stable lewis structure minimizes the number and magnitude of formal charges

Question 23

in a lewis structure, what atom takes the center position?

Answer 23

the least elecneg atom

Question 24

a lewis structure with what type of separation between opposite charges is preferred?

Answer 24

a lewis structure with less separation between opposite charges is preferred over a lewis structure with a large separation of opposite charges

Question 25

why can elements in the third period form more than four bonds

Answer 25

all elements in the 3rd period or beyond can form more than four bonds because they can take on more than eight electrons, which go into the d subshell and help them form more than four bonds

Question 26

In VSEPR why do the electron pairs arrange or rather need to be arranged as far apart as possible?

*Know the VSEPR theory chart from page 91
know the difference between molecular and electronic geometry

Answer 26

they do this to minimize repulsive forces

Question 27

what is the difference between the electronic and molecular geometry?
what is the coordination number

Answer 27

electronic geometry describes the spatial arrangement of all pairs of electrons around the central atom, including bonding and lone pairs while Molecular geometry describes the spatial arrangement of ONLY the bonding pairs of electrons.

the c number is the number of atoms that surround and are bonded to a central atom And is important for molecular geometry

Question 28

why do nonbonding e- pairs exert more repulsion than bonding pairs?

Answer 28

they do this because these electrons rside closer to the nucleus

Question 29

why might a compound with polar bonds be polar or nonpolar?

Answer 29

This depends on how the polar bonds are spaced in the molecule

Question 30

order of intermolecular force strength??

Answer 30

weakest: they are the dispersion or london forces
intermediate strength: dipole-dipole interactions
strongest: hydrogen bond
ultimate strongest: covalent bond

Question 31

what type of forces are the attractive and repulsive interactions of short-lived and rapidly shifting dipoles

Answer 31

they are london dispersion forces

Question 32

why do large molecules have reater dispersion forces than small molecules?

Answer 32

they do because they are more easily polarizable

Question 33

what type of IF force exists between noble gas atoms?

Answer 33

london dispersion forces(this is why noble gases liquefy at room temp)

Question 34

why are dipole-dipole interactions negligible in the gas phase

Answer 34

they are negligible becuz of increased distance between the gas particles

Question 35

what type of bond is a hydrogen bond

Answer 35

dipole dipole

Question 36

describe hydrogen bonds

Answer 36

whne hydrogen is bonded to F O or N, the hydrogen atom carries only a small portion of the electron density

Question 37

describe hydrogen bonds

Answer 37

whne hydrogen is bonded to F O or N, the hydrogen atom carries only a small portion of the electron density

Question 38

What is the fundamental unit of charge for the proton and electron?

Answer 38

1.6 x 10^-19 (negative for electrons)

Question 39

what is the mass of one proton?

Answer 39

1 amu

Question 40

name the three isotopes of hydrogen and their p’s and n’s.

Answer 40

protium- 1 p, 0 n and mass # of 1
deuterium- 1 p, 1 n and mass # of 2
tritium- 1 p, 2 n, and a mass # of 3

Question 41

define a mole

give an example related to this with the Carbon atom which has a mass of 12 amu

Answer 41

a mole is a number of things equal to Avogadro’s number 6.02 x 10^23
carbon has a mass of 12 amu, which means that the average carbon atom has a mass of 12 amu and 6.02 x 10^23 carbon atoms have a mass of 12 g

Question 42

the energy of a quantum is given by the planck relation…what is the relation’s equation and what does each thing stand for? value for planck’s constant?

Answer 42

E = hf
e is the energy of a quantum, h is Planck’s constant and f is frequency of the radiation
h= 6.626 x 10^-34

Question 43

kinetic energy equation=

Answer 43

K= 1/2mv^2

Question 44

possible values for the angular momentum of an electron orbiting a hydrogen nucleus could be given by:

energy of an electron eqn:
and why the negative sign in the eqn?

Answer 44

L=nh/2pi n is the principle quantum number(any positive integer); h is planck’s constant

energy of an electron eqn: E= -Rh/n^2
Rh is the Rydberg unit of energy(2.18 x 10^-18), n is principal quantum #

there is a neg sign in the eqn because the electron will ALWAYS have an attractive force to the proton

Question 45

what fact does the -Rh/n^2 confirm

Answer 45

confirms that the energy of an electron goes up, the farther out from the nucleus that it is located(increasing n)

Question 46

what is the principle quantum number for the ground state of an atom?

when an electron is promoted to an orbit with a larger radius(higher energy), what is the condition of the atom?

Answer 46

it is n=1

the atom is in the excited state

Question 47

when atom in excited state, what spectrum is it

mnemonic for emission spectrum:

Answer 47

emission spectrum
as electrons go from a lower energy to a higher energy, they get AHED
A=absorb light
H=higher potential
E= Excited
D= distant(from the nucleus)

Question 48

electromagnetic energy of photons that are what’ed can be found using this eqn
what happens when an electron returns back to the ground state?

Answer 48

its the elecmag energy of photons that are emitted and can be found using E= hc/lambda
the electron will emit a photon with a particular wavelength

Question 49

the group of hydrogen what’ion lines corresponding to transitions from energy levels n is greater than or equal to 2 to n=1 is known as the ? from energy levels n is greater than or equal to 3 to n=2? from energy levels n is greater than or equal to 4 to n=3,

Answer 49

emission lines

Lyman; Balmer; Paschen

Question 50

the energy when n changes from a what’er initial value to a what’er final value is given by what equation?
when an electron is excited to a higher energy level, what must it do?

Answer 50

-Rh=[1/n^i2-1/n^f2]

it must absorb the right amount of energy to make that transition

Question 51

when an electron is excited to a higher energy level, what must it do?
what does the heisenberg uncertainty principle state?
what does the pauli exclusion principle state?

Answer 51

its impossible to pinpoint the exact momentum and position of an electron
the pauli exclusion principle states that no two electrons can possess the same set of four quantum numbers

Question 52

the larger the value of n for an electron, what two things are also higher?
within each shell, there is a capacity to hold a certain number of electrons, given by:
what happens to the difference in energy btween two shells as the distance from the nucleus goes up and why?

Answer 52

the higher the value for n, the higher the energy level and and radius of the electron’s shell
given by: max number of electrons within a shell= 2n^2
n is the principal quantum number
this difference goes down»why? because the difference is a function of [1/n^i2-1/n^f2]

Question 53

what two things does the azimuthal quantum number(angular momentum quantum number) refer to
for any given value of n, what is the value for l?
example of this: if n is 1, what is the value for l? if n is 2, what is l?
what is an easier way to remember the values for l, given any n AND two examples?

Answer 53

it refers to the shape and number of subshells within a given principal energy level
this value for l would be: l is 0 to n-1
(examples) l is 0; l is 0 and 1
the easier way is to say: the n value tells you the number of subshells So there is:
only 1 subshell (l=0) in the first principal energy level; there are two subshells (l=0 and 1) in the second principal energy level

Question 54

what is spectroscopic notation and how does it work(give all FIVE examples)?
fifth example: an electron in the shell n=4 and subshell l=2 would be in what subshell?

Answer 54

it refers to the shorthand way to write the n and l numbers; the principal quantum number stays a number BUT the azimuthal quantum number is designated by a letter: l=0 subshell is called s; l=1 subshell is called p, the l=2 subshell is called d, and the l=3 subshell is called f
5TH EXAMPLE: it would be in the 4d subshell

Question 55

within each subshell, how do you find the capacity to hold a certain number of electrons
what does ml specify; how many electrons can each orbital hold? what are the possible values of ml? for any value of l, what eqn gives you the possible values for ml?

Answer 55

max number of electrons within a subshell= 4l + 2
the magnetic quantum number ml specifies the orbital of the electron; each orbital can hold a max of 2 electrons; possible values of ml are -l to l, including 0; 2l +1

Question 56

how many groups of elements do the s, p, d and f blocks contain?

Answer 56

s contains 2 elements in each row of the PT, p contains 6 groups of elements, d contains 10 elements and f contains 14 elements

Question 57

when two electrons are in the same orbital, what must they have opposite of? in this case, what are they said to be? if they have the same ms values what are the electrons said to have?

Answer 57

opposite spins; in this case they are said to be paired.

they are said to have parallel spins

Question 58

KNOW THE ELEC CONFIG CHART AND HOW TO DO IT!!!!!

study it from page 22 and know it by heart(write it out/memorize it for this flashcard)

Answer 58

KNOW THE ELEC CONFIG CHART AND HOW TO DO IT!!!!!

Question 59

how do electrons fill and according to what principle?
whats a cool rule to remember how the electrons fill up and what does it say? what if 2 subshells have the same value?
Example: what will fill first the 5d or 6s subshell and why?

Answer 59

they fill from lower to higher energy according to the Aufbau principle(building up principle)
a cool rule to remember the way that the electrons fill subshells is the n + l rule, which states that the lower the values for the first and second quantum numbers, n + l, the lower the energy of the subshell; if two subshells have the same n + l value, the subshell with the lower n + l value has a lower energy and will fill with electrons first
example answer: use the n +l rule and whichever one has the lowest n+l value will have the lower energy and fill first

Question 60

what are the lowest subshells for s, p, d and f?
how do you write the elec config of an ion(give steps), what if theres a tie?
how do orbitals fill for subshells with more than one orbital and according to what prinicple?

Answer 60

they are 1s, 2p, 3d, and 4f
write the elec config for the parent element first; then, for a cation, remove electrons from the subshells with the highest value for n, if theres a tie btween, then remove electrons from the subshell with the highest value for l
in subshells that contain more than one orbital, like the 2p subshell with its 3 orbitals, the orbitals will fill acc to Hund’s rule, which states that within a subshell, orbitals are filled so that there are a max number of half filled orbitals with parallel spins.

Question 61

acc to hunds rule, what would electrons prefer to have?

Answer 61

they would prefer to have their own seat(orbital) before being forced to share one

Question 62

what is the basis for electron repulsion?
what can we say about the energy of half filled and fully filled orbitals? and what 2 IMPORTANT exceptions does this bring to mind?
elaborate more on the exceptions in regards to the supposed and actual elec configs for the two exception elements and what electron shifts take place to make this possible

what other elements can have such shifts of electrons? which elements cannot?

Answer 62

the basis for electron repulsion is that electrons in the same orbital tend to be closer and thus repel each other more than electrons placed in diff orbitals
-half-filled and fully filled orbitals have lower energies(higher stability)»The exceptions this brings to mind is Chromium and other elements in its group and copper and other elements in its group

Chromium(Z=24) is supposed to have an elec config of [Ar]4s^23d^4(but its really supposed to be [Ar]4s^13d^5, but moving one electron from the 4s subshell to the 3d subshell, which lets the 3d subshell be half filled; though this electron movement from 4s to 3d is energetically unfavorable, but the extra stability from making the 3d subshell half filled outweighs that cost
Copper(Z=29) is supposed to have an elec config of [Ar]4s^13d^10 instead of [Ar] 4s^23d^9; in this case, a full d subshell outweighs the cost of moving an e out of the 4s subshell; other elements in the same group have similar behavior, moving one electron from the highest s subshell to the highest d subshell

elements in the f subshell can experience these e shifts but not p subshell becuz the extra stability does not outweigh the cost

Question 63

how will materials made of unpaired electrons orient their spins? what will happen and what are these materials considered to be?

Answer 63

they will orient their spins in alignment with a magnetic field and the material will be weakly attracted to the field; these materials are considered paramagnetic

Question 64

paramagnetic means that a magnetic field will cause what spins and what’ed electrons, which will cause what?
materials that are made of atoms that have only paired electrons will be slightly what’ed by a magnetic field and are said to be what

Answer 64

paramagnetic means that a magnetic field parallel spins and unpaired electrons and therefore cause an attraction

materials that are made of atoms that have only paired electrons will be slightly repelled by a magnetic field and are said to be diamagnetic