Chemistry test 3

Why are the electron affinities of noble gases highly positive?

Noble gases have a full octet, so adding an additional electron is unfavorable. Adding another electron would be highly endothermic.

Which of the following statements about radio waves is false? Radio waves are used extensively for communication. AM and FM radio stations broadcast different frequencies of radio waves. Radio waves are a type of nonionizing radiation. Radio waves range in frequency from about 3×1011 Hz to 3×108 Hz.

Radio waves range in frequency from about 3×1011 Hz to 3×108 Hz.

Which element has the electron configuration [Kr]5s24d105p2? Sn Sb In Cd

Sn

what the reactivity trend for the periodic table

The farther to the left and down the periodic chart you go, the easier it is for electrons to be given or taken away, resulting in higher reactivity. Period - reactivity increases as you go from the left to the right across a period. Group - reactivity decreases as you go down the group.

Wavelength is the _____.

distance between corresponding points on two adjacent waves

The aufbau principle states that _____.

electrons fill the lowest energy orbital first and fill additional orbitals in order of increasing energy

electron affinity

increases upward for the groups and from left to right across periods of a periodic table because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons.

The Heisenberg uncertainty principle states that

it is impossible to simultaneously know the precise position and velocity of a particle

What Quantum numbers stand for for n and l

n- # ,determines the colum or which element l- the orbital in use for example, 0=s, 1=p, 2=d, 3=f

Atomic radius increases _____ across a period and _____ a group.

right to left ; down

The angular momentum quantum number describes the _____.

shape of an orbital

The principal quantum number(N) describes the _____.

size of an orbital

frequency is

the number of complete wavelengths that pass a point in a given time

Pauli Exclusion Principle

An atomic orbital may describe at most two electrons, each with opposite spin direction

Why are the electron affinities of Be and Mg highly positive?

Be and Mg have a full s sublevel, so it is not favorable to add another electron. This causes highly positive electron affinities.

Identify the relationship between ionization energy of singly charged anions and electron affinity of the neutral atom.

Electron affinity decreases as ionization energy decreases. Singly charged anions are in group 7A. Electron affinity and ionization energy both decrease down the group.

composed of both ions and atoms, ranked correctly from smallest to largest size according to ionic and atomic radius.

F, F−, Ca2+, Ca Atomic radius increases down a group and from right to left across a period. Cations are smaller than the parent atom and anions are larger than the parent atom. Based on atomic radius, Ca is larger than F and based on ionic radius, F− is larger than F and Ca2+ is smaller than Ca.

Which statement correctly describes the relationship between frequency and wavelength?

Frequency and wavelength are inversely proportional. When the frequency increases, the wavelength decreases.

whats the atomic radius trend in the periodic table?

In Metals:: Period - reactivity decreases as you go from left to right.Group - reactivity increases as you go down a group In Non-metals: Period - reactivity increases as you go from the left to the right.Group - reactivity decreases as you go down the group.

A photon has an energy of 8.7×10−19 J. What is its wavelength in meters? 2.3×10−7 m 0.23 m 1.3×1015 m 1.7×10−43 m

The energy of a photon and wavelength are related by the equation E=hcλ or λ=hcE, where h is Planck's constant and c is the speed of light in vacuum. Planck's constant is 6.626×10−34 J⋅s and the speed of light in vacuum is 2.9979×108 m/s.λ=(6.626×10−34 J⋅s)×(2.9979×108 m/s)8.7×10−19 J=2.3×10−7 m

Which mathematical equation correctly describes the relationship between wavelength and frequency?

Wavelength= speed of light/ frequency

Why does ionization energy decrease moving down a group in the periodic table? A)because the atoms get closer to noble gas configuration B)because effective nuclear charge increases C)because the outer electrons get further from the nucleus D)because nuclear charge decreases E)because shielding decreases

because the outer electrons get further from the nucleus

The quantum number n=2 describes _____ orbitals.

four Within the shell n=2 there are two possible subshells, ℓ=0 and ℓ=1. ℓ=0 indicates a 2s orbital, which has only one possible value for mℓ or one possible orbital. ℓ=1 indicates a 2p orbital, which has three possible values for mℓ or three possible orbitals. In total, n=2 could represent four different orbitals.

The quantum numbers n=2 and ℓ=1 describe _____ orbital(s). two three four one

n=2 and ℓ=1 designates a 2p orbital; however, p orbitals can be oriented differently in three-dimensional space. The magnetic quantum number, mℓ, designates the orientation and can be any integer between −ℓ and ℓ. So for ℓ=1 there are three possible values for mℓ: −1, 0, 1

Which set of quantum numbers describes a 4s orbital? Please choose the correct answer from the following choices, and then select the submit answer button. n=4 and ℓ=1 n=3 and ℓ=0 n=4 and ℓ=3 n=4 and ℓ=0

n=4 and ℓ=0 When designating the subshell of an orbital, the principal quantum number is reported first. The angular momentum quantum number determines the shape of the orbital, and the shape is what is reported. s orbitals are designated by ℓ=0. So a 4s orbital would be described by n=4 and ℓ=0.

Frequency is the _____

number of waves that pass a point per unit of time Frequency is also defined as the number of cycles per unit time.

The Aufbau principle states that an electron

occupies the lowest available energy level

Hund's rule states that

orbitals which are equal in energy (degenerate orbitals) should each contain one electron before filling with a second electron

Hund's rule states that _____. A)orbitals which are equal in energy (degenerate orbitals) should each contain one electron before filling with a second electron B)electrons in the same orbital must have opposing spin C)electrons are likely to be found in a certain three-dimensional space around the nucleus, and that space is described by quantum numbers D)electrons fill the lowest energy orbital first and fill additional orbitals in order of increasing energy

orbitals which are equal in energy (degenerate orbitals) should each contain one electron before filling with a second electron Hund's rule also states that total spin should be maximized, meaning that electrons in singly occupied orbitals should all spin in the same direction.

the magnetic quantum number describes the _____.

orientation of the orbital in three-dimensional space

Determine all the possible electron spin quantum numbers if n=2.

−1/2, +1/2 The electron spin quantum number can be only +1/2 or −1/2. The electron spin quantum number is independent of all other quantum numbers.

Determine all the possible magnetic quantum numbers if ℓ=2. 0, 1 −2, −1, 0 0, 1, 2 −2, −1, 0, 1, 2

−2, −1, 0, 1, 2 The magnetic quantum number can be any integer between −ℓ and ℓ. So for ℓ=2, the magnetic quantum number can be −2, −1, 0, 1, or 2.

Which statement correctly describes the relationship between the energy of a photon and frequency? A)Energy and frequency are directly proportional. When energy increases, frequency also increases. B)Energy and frequency are inversely proportional. When energy increases, frequency decreases. C)Energy and frequency have an exponential relationship. When energy increases, frequency increases exponentially. D)Energy and frequency have an exponential relationship. When energy increases, frequency decreases exponentially.

A)Energy and frequency are directly proportional. When energy increases, frequency also increases.

Why are the electron affinities of the halogens the most negative? A)Halogens have a low Zeff. B)Adding an electron would give halogens 9 electrons. C)Adding an electron would give halogens a full s sublevel. D)Adding an electron would give halogens a noble gas configuration.

Adding an electron would give halogens a noble gas configuration. Halogens have 7 valence electrons, so adding another electron would give them a noble gas configuration of 8 valence electrons. Having 8 valence electrons is more favorable than having 7, so they would have a highly negative electron affinity.

An element in the excited state has the electron configuration [Ne]3s23p44s1. This is the electron configuration for an excited state of _____.

Chlorine has seven valence electrons and its ground state electron configuration is [Ne]3s23p5. In the excited state, one of chlorine's seven valence electrons is promoted to a higher-energy orbital. In this case that is the next highest energy orbital, the 4s orbital. This is only one of many possible excited state configurations for chlorine as the electron could be promoted to any higher energy orbital.

The ionization energy of singly charged anions _____ as electron affinity of the neutral atom _____.

Decreases; decreases

Which quantum number describes the orientation of an orbital in three-dimensional space?

The magnetic quantum number, mℓ, describes the orientation of an orbital within three-dimensional space and can be any integer between −ℓ and ℓ.

Which quantum number describes the orientation of an orbital in three-dimensional space?

The magnetic quantum number, mℓ, describes the orientation of an orbital within three-dimensional space and can be any integer between −ℓ and ℓ.(angular momentum)

Identify the reason atomic radius increases down a group. A)The effective nuclear charge decreases, causing the attraction between the nucleus and electrons to be stronger. B)The principal quantum number of the electrons in the outermost energy level increases, causing larger orbitals. C)The principal quantum number of the electrons in the outermost energy level decreases, causing smaller orbitals. D)The effective nuclear charge increases, causing the attraction between the nucleus and electrons to decrease.

The principal quantum number of the electrons in the outermost energy level increases, causing larger orbitals. Atomic radius increases down a group because orbitals get larger.

The quantum numbers n=4, ℓ=2 and mℓ=−1 describe _____ electron(s).

The quantum numbers n=4 and ℓ=2 describe a 4d orbital, and mℓ describes the orientation in three-dimensional space. Only two electrons can have the same n, ℓ, and mℓ quantum numbers. One of the electrons would have a spin of +1/2 and the other would have a spin of −1/2.