Chemistry Atomic and Molecular Structure

Question 1

The ___ is the basic building block of matter, representing the smallest unit of a chemical element

Answer 1

atom

Question 2

The ___ and neutrons in an atom form the nucleus, the core of the atom

Answer 2

protons

Question 3

The ___ exist outside the nucleus in characteristic regions of space called orbital

Answer 3

electrons

Question 4

According to John Dalton, all ___ are composed of very small particles called atoms

Answer 4

elements

Question 5

According to John Dalton, all ___ are composed of atoms of more than one element

Answer 5

compounds

Question 6

According to John Dalton, for any given compound, the ___ of the numbers of atoms of any two of the elements present is either an integer or a simple fraction

Answer 6

ratio

Question 7

According to John Dalton, a given chemical reaction involves only the ___, combination, or rearrangement of atoms; it does NOT result in the creation or destruction of atoms

Answer 7

separation

Question 8

The ___ (Z) of an element is equal to the number of protons found in an atom of that element

Answer 8

atomic number

Question 9

___ carry no charge and have a mass only slightly larger than that of protons, so they can still be considered to have a mass of approximately 1 u

Answer 9

neutrons

Question 10

Different ___ of one element have different numbers of neutrons but the same number of protons

Answer 10

isotopes

Question 11

The farther the ___ electrons are from the nucleus, the weaker the attractive force of the positively charged nucleus and the more likely the valence electrons are to be influenced by other atoms

Answer 11

valence

Question 12

Therefore, the atomic number indicates the number of ___ in a neutral atom

Answer 12

electrons

Question 13

A positive or negative ___ on an atom is due to a loss or gain of electrons; the result is called an ion

Answer 13

charge

Question 14

Note that a (+) charge indicates a loss of negatively-charged electrons , whereas a (-) charges indicates a ___ of electrons

Answer 14

gain

Question 15

The atomic ___ (A) of an atom is equal to the total number of nucleons (protons an neutrons)

Answer 15

mass number

Question 16

mass number (A) = number of protons + ___

Answer 16

number of neutrons

Question 17

On a larger scale, the ___ is the weight in grams per one mole (mol) of a given element (g/mol)

Answer 17

molecular weight

Question 18

A ___ is a unit used to count particles and is represented by Avogadro’s number, 6.02 x 10^23 particles per mol

Answer 18

mole

Question 19

___ are referred to either by the convention described above or, more commonly, by the name of the element followed by the mass number

Answer 19

isotopes

Question 20

In 1900, Max Planck developed the first ___, proposing that energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta

Answer 20

quantum theory

Question 21

The ___ of the electron is related to its orbital radius: the smaller the radius, the lower the energy state of the electron

Answer 21

energy

Question 22

At the ___ level, the electron is in its lowest energy state

Answer 22

ground state

Question 23

Because each element can have its electrons excited to different distinct energy levels, each element possesses a unique ___, which can be used as a fingerprint

Answer 23

atomic emission spectrum

Question 24

When an electron is excited to a higher energy level, it must ___ energy

Answer 24

absorb

Question 25

The ___ absorbed as an electron jumps from an orbital of low energy to one of higher energy is characteristic of that transition

Answer 25

energy

Question 26

The excitation of electrons in a particular element results in energy absorptions at ___ wavelengths

Answer 26

specific

Question 27

Thus, in addition to an ___, every element possesses a characteristic absorption spectrum

Answer 27

emission spectrum

Question 28

Absorption spectra can thus be used in the identification of elements present in a gas ___ sample

Answer 28

phase

Question 29

While the concepts put forth by Bohr offered a reasonable explanation for the structure of the hydrogen atom and ions containing only one ___ (such as He+ and Li2+), they did not explain the structures of atoms containing more than one electron

Answer 29

electron

Question 30

Due to the flaws in the Bohr model, this is because Bohr's ___ does not take into consideration the repulsion between multiple electrons surrounding one nucleus

Answer 30

model

Question 31

An orbital is a ___ of the probability of finding an electron within a given region

Answer 31

orbital

Question 32

In the current ___ description of electrons, pinpointing both the exact location and momentum of an electron at any given point in time impossible

Answer 32

quantum mechanical

Question 33

The idea of an electron's position not being quite known, this idea is best described by the ___ which states that it is impossible to simultaneously determine, with perfect accuracy, the momentum (defined as mass times velocity) and the position of an electron

Answer 33

heisenberg uncertainty principal

Question 34

Concerning the Heisenberg uncertainty principal, this means that if the ___ of the electron is being measured accurately, its position will not be certain, and vice versa

Answer 34

momentum

Question 35

___ states that any electron in an atom can be completely described by four ___: n, l,m sub l, and m sub s

Answer 35

modern atomic theory

Question 36

Furthermore, according to the pauli exclusion principle, no two ___ in a given atom can possess the same set of four quantum numbers

Answer 36

electrons

Question 37

The ___ and energy of an electron described by its quantum numbers is known as its energy state

Answer 37

position

Question 38

The ___ of n limits the values of l, which in ___ limit the values of m sub l

Answer 38

value

Question 39

The values of three of the ___ qualitatively give information about the orbitals: n about the size, l about the shape, and m sub l about the orientation of the orbital

Answer 39

quantum numbers

Question 40

Think of the ___ as becoming more specific as one goes from n to l to m sub l to m sub s

Answer 40

quantum numbers

Question 41

The first quantum number is commonly known as the ___ and is denoted by the letter n

Answer 41

principal quantum number

Question 42

The first quantum number, this is the quantum number used in Bohr's model that can theoretically take on any positive integer value and represents the ___ where an electron is present in an atom

Answer 42

shell

Question 43

The maximum n that can be used to describe the ___ of an element at its ground state corresponds with that element's period (row) in the periodic table

Answer 43

electrons

Question 44

Nitrogen is in period 2, so neutral Nitrogen in its ground state has ___ with n values of 1 and 2

Answer 44

electrons

Question 45

The larger the integer value of n, the ___ the energy level and radius of the electron's orbit

Answer 45

higher

Question 46

The ___ number of electrons in an electron shell n is 2n^2

Answer 46

maximum

Question 47

The difference in energy between ___ shells decreases as the distance from the nucleus increases

Answer 47

adjacent

Question 48

The ___ difference between the third and fourth shells (n=3 and n=4) is less than that between the second and third shells (n=2 and n=3)

Answer 48

energy

Question 49

The second quantum number is called the ___ and is designated by the letter l

Answer 49

azimuthal (angular momentum) quantum number

Question 50

The second quantum number, this tells us the shape of the ___ and refers to the subshells or sublevels that occur within each principal energy level

Answer 50

orbitals

Question 51

For any given n, the ___ of l can be any integer in the range of 0 to n-1

Answer 51

value

Question 52

The four ___ corresponding to l=0,1,2,and 3 are known as the sharp, principal, diffuse, and fundamental subshells, or s,p,d, and f subshells respectively

Answer 52

subshells

Question 53

The greater the value of l, the ___ the value of the subshell

Answer 53

greater

Question 54

However, the ___ of subshells from different principal energy levels may overlap

Answer 54

energies

Question 55

For example, the 4s subshell will have a lower energy than the 3d subshell because its average distance from the ___ is smaller

Answer 55

nucleus

Question 56

The first two columns (of the periodic table) show the atoms that have their ___ electrons in the s subshell

Answer 56

valence

Question 57

The right "block" of the ___ table represents atoms that are filling the six spaces in the p subshell

Answer 57

periodic

Question 58

Columns 3-12 represent the d block, and the Lanthanide and ___ series are the f block

Answer 58

Actinide

Question 59

The third quantum number is the ___ and is designated m sub l

Answer 59

magnetic quantum number

Question 60

As far as the third quantum number is concerned, this number describes the orientation of the ___ in space

Answer 60

orbital

Question 61

An orbital is a specific ___ within a subshell that may contain no more than two electrons

Answer 61

region

Question 62

The ___ specifies the particular orbital within a subshell where an electron is highly likely to be found at a given point in time

Answer 62

magnetic quantum number

Question 63

The possible ___ of m sub l are all integers from l to -l including 0

Answer 63

values

Question 64

Therefore, the s subshell (l=0), has only one possible ___ of m sub l (0) and will contain one orbital; in contrast, the p subshell (l=1) has three possible m sub l values (-1, 0, +1) and three orbitals

Answer 64

value

Question 65

The d subshell (l =2) has five possible m sub l values (-2,-1,0,+1,+2) and five orbitals; the f subshell (l=3) has seven possible m sub l values (-3,-2,-1,0,+1,+2,+3) and contains ___ orbitals

Answer 65

seven

Question 66

The ___ and energy of each orbital are dependent upon the subshell in which the orbital is found

Answer 66

shape

Question 67

A p subshell with its three possible m sub l values (-1,0+1) has three dumbbell-shaped orbitals that are ___ in space around the nucleus along the x, y, and z axes

Answer 67

oriented

Question 68

Each p subshell has these three ___, they are often referred to as p sub x, p sub y, and p sub z

Answer 68

orbitals

Question 69

The fourth quantum number is also called the ___ and is denoted by m sub s

Answer 69

spin quantum number

Question 70

The ___ of a particle is its intrinsic angular momentum and is a characteristic of a particle

Answer 70

spin

Question 71

The two spin orientations are ___ +1/2 and -1/2

Answer 71

orientations

Question 72

Whenever two electrons are in the same orbital, they must have opposite spins due to the ___ exclusion principle

Answer 72

pauli

Question 73

Electrons in different ___ (different m sub l values) with the same m sub s values are said to have parallel spins

Answer 73

orbitals

Question 74

Electrons with opposite spins (different m sub s values) in the same orbital (same m sub l value) are often ___ to as paired

Answer 74

referred

Question 75

For a given atom or ion, the pattern by which ___ are filled and the number of electrons within each principal level and subshell are designated by an electron configuration

Answer 75

subshells

Question 76

In ___ notation, the first number denotes the principal energy level, the letter designates the subshell, and the superscript gives the number of electrons in that subshell

Answer 76

electron configuration

Question 77

According to the ___ principle, subshells are filled from lowest to highest energy, and each subshell will fill completely before electrons begin to enter the next one

Answer 77

aufbau

Question 78

The (n+l) rule is used to ___ subshells by increasing energy

Answer 78

rank

Question 79

Pertaining to the (n+l) rule, this rule states that the lower the sum of the first and second ___, the lower the energy of the subshell

Answer 79

quantum numbers

Question 80

If two ___ possess the same (n+l) value, the subshell with the lower n value has a lower energy and will fill first

Answer 80

subshells

Question 81

Similar to a greyhound bus filling up, ___ will go to empty orbitals before pairing up

Answer 81

electrons

Question 82

In the case of uncharged atoms, the number of ___ equals the atomic number

Answer 82

electrons

Question 83

If the atom is ___, the number of electrons is equal to the atomic number plus the extra electrons if the atom is negative or the atomic number minus the missing electrons if the atom is positive

Answer 83

charged

Question 84

In ___ that contain more than one orbital, such as the 2p subshell with its three orbitals, the orbitals will fill according to Hund's rule

Answer 84

subshells

Question 85

Hund's rule states that, within a given ___, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins

Answer 85

subshell

Question 86

Electrons "prefer" empty orbitals to half-filled ones because a pairing ___ must be overcome for two electrons carrying repulsive negative charges to exist in the same orbital

Answer 86

energy

Question 87

The presence of paired or unpaired electrons affects the chemical and ___ properties of an atom or molecule

Answer 87

magnetic

Question 88

If the material has unpaired electrons, a magnetic field will ___ the spins of these electrons and weakly attract the atom to the field

Answer 88

align

Question 89

___ which have aligned magnetic fields and that have electrons which weakly attract the atom to the field are paramagnetic

Answer 89

materials

Question 90

Materials that have no unpaired ___ and are slightly repelled by a magnetic field are said to be diamagnetic

Answer 90

electrons

Question 91

The valence electrons of an atom are those electrons that exist in its outer ___ shell or that are available for chemical bonding

Answer 91

energy

Question 92

For elements in Groups IA and IIA, only the ___ s electrons are valence electrons

Answer 92

outermost

Question 93

For elements in Groups IIIA through VIIIA, the outermost s and p electrons in the highest energy ___ are valence electrons

Answer 93

shell

Question 94

For transition elements, the valence electrons are those in the outermost s subshell and in the d subshell of the ___ energy shell

Answer 94

next-to-outermost

Question 95

For the inner transition elements (the lanthanide and actinide series), the valence electrons are those in the s subshell of the outermost energy shell, the d subshell of the next-to-outermost energy shell, and the f ___ of the energy shell two levels below the outermost shell

Answer 95

subshell

Question 96

Atoms with half-filled and ___subshells are extremely stable

Answer 96

fully-filled

Question 97

Atoms with half filled and fully filled ___ are stable, so much so that some molecules will move electrons from a lower energy subshell into higher one to half fill the subshell

Answer 97

subshells

Question 98

For ___: it would be expected to have a valence shell configuration of 4s2 3d4. However, if it moves one s electron into the d subshell, then both subshells will be half filled. So, in reality, Cr exists as 4s1 3d5. The same thing is true for all other elements in column 6

Answer 98

chromium

Question 99

All atoms in column 11 will move one electron to complete the d subshell and, as a result, have a half-filled s ___Copper (Cu) will exist as 4s1 3d10

Answer 99

subshell