Chem unit 10 electron configuration

What are the core electrons in phosphorus?

1s2 2s2 2p6

Valence electrons are in the highest energy level

and generally participate in the formation of chemical bonding.

What is the electron configuration for Cl−?

1s22s22p63s23p6

What is the electron configuration for K+?

1s22s22p63s23p6

What is the electron configuration for O2−?

1s^2 2s^2 2p^6

What are the valence electrons in cobalt's electron configuration?

4s^2 3d^7

How many boxes are required to depict the 4f orbitals?

7

A cation or anion is called isoelectronic with another element (or ion) when it has the same number of electrons with it.

For example, Rb+ is isoelectronic with krypton because it has lost its 5s electron and attained the same electron configuration as krypton.

Which element has the core electrons 1s22s22p6? He O Be Na

Na

Pauli exclusion principle:

No two electrons in the same atom can have the same set of four quantum numbers.

Which of the following species has the largest radius? O2− F− Ne Na+

O^2

Which will have an abbreviated electron configuration beginning with the radon core?

Pu

In which of the following element blocks does the atomic radius generally not tend to increase when moving down within a group? s block p block d block The atomic radius generally increases when going down a group in all of the above element blocks.

The atomic radius generally increases when going down a group in all of the above element blocks.

Core electrons are not involved in

bonding and are found in the inner shell orbitals.

The electrons most responsible for shielding in an atom are the __________.

core electrons The core electrons shield the valence electrons from the nuclear charge because they are positioned between the protons and the valence electrons.

The __________ is one-half the distance between the nuclei of two identical atoms when joined by a covalent bond.

covalent radius

Atomic radius increases

down and left

The covalent radius generally increases when moving in which directions on the periodic table?

down and left

Which of the following have the last electron added in an s or p orbital?

main group elements

Pauli exclusion principle,

which states that no two electrons in an atom can have the same set of four quantum numbers

What is the electron configuration for Ru^3+

1s22s22p63s23p64s23d104p64d5 The electron configuration for Ru is [Kr]5s14d7 but Ru3+ loses three electrons, so it will become [Kr]4d5. It should be noted that Ru has what is called an anomalous configuration, as there is only one electron in the 5s subshell. A number of transition metals have anomalous configurations including copper, chromium, and platinum, among many others.

What are the CORE electrons in cobalt's electron configuration?

1s^2 2s^2 2P^6 3S^2 3p^6 Argon has the electron configuration of: 1s22s22p63s23p6 which means that these electrons are stable and do not take part in bonding, so these are the core electrons.

What is the electron configuration for the core electrons in bromine?

1s^2 2s^2 2p^6 3s^2 3p^6

What is the electron configuration of Na+? (select all that apply)

1s^2 2s^2 2p^6 and Ne

Which would be an invalid listing within an electron configuration? 6s1 4f13 4p5 2d5

2d^5

Which of the following notations indicates 3 electrons?

2p3 2p3 indicates 3 electrons since electrons are indicated in the superscript.

Nonmetals gain electrons in order to gain:

noble gas electron configuration

Which element has an electron configuration ending in 4d2?

Zr

What is the electron configuration for Zn2+?

1s22s22p63s23p63d10 The Zn cation loses 2 electrons to form Zn2+. The electron configuration of Zn is 1s22s22p63s23p64s23d10. Note that because zinc is a transition metal, it will lose the 4s electrons before the 3d electrons. Therefore, the electron configuration of Zn2+ is 1s22s22p63s23p63d10.

Which of the following energy trends is NOT correct? s<p<d<f 6s<6p<6d<5f 4p<5s<4d<5p 4s<3d<4p<5s

6s<6p<6d<5f Instead of 6s<6p<6d<5f, the orbitals following the 6s orbital in energy are as follows: 6s<4f<5d<6p.

What are the core electrons of strontium?

Strontium's full electron configuration is 1s22s22p63s23p64s23d104p65s2. To find its core electrons, we must separate the valence electrons (in this case, 5s2) from all of the complete principal energy level shells (the configuration of the closest noble gas). Thus we isolate the electron configuration of krypton, 1s22s22p63s23p64s23d104p6, from the full electron configuration of Sr. These are its core electrons, which are virtually unreactive as they constitute full octets.

The term nuclear charge refers to the precise charge of the nucleus, which, in units of fundamental charge, is equal to the number of protons, Z. The term effective nuclear charge is used to mean the apparent charge that determines the radius of the outermost electron(s) in an atom. Which quantity below can be used to approximate the effective nuclear charge by accounting for shielding by the inner electrons?

Z− the number of shielding electrons If Z is the number of protons, then we must subtract from it the number of shielding electrons to find the remaining positive charge that is attracting the valence electrons, which we call the effective nuclear charge.

Most exceptions to the trend of decreasing radius moving to the right within a period occur in the __________.

d block

Which are the valence electrons for tellurium?

5s^2,5p^4 Tellurium is in the fifth period and the fourth element in the p block, so it will have two valence electrons in the 5s orbital and four in the 5p orbitals.

Consider the following electron configurations. Element A: 1s22s1 Element B: 1s22s22p63s1 Element C: 1s22s22p63s23p64s1 Which of the following is the correct order for decreasing IE1 (i.e., largest to smallest)?

A>B>C Elements A,B, and C all belong to the same group (1st group indicated by the valence s orbital). Because atomic radius increases with increasing n (A=2,B=3, and C=4) and IE decreases with increasing atomic radius, we know that ionization energy decreases from A to B to C.

Which of the following may contribute to the increased radius of an anion compared to parent atom?

Additional electrons lead to more electron-electron repulsion, which will increase the average distances of all the outer orbitals from the nucleus. Additional electrons may need to occupy higher-energy orbitals, which are farther from the nucleus than the lower-energy orbitals.

Given: Al^3+

Aluminum will lose three electrons when it forms an ion as indicated by its positive (+3) charge. A neutral atom of aluminum has 13 electrons; the ion of aluminum, Al3+ , has lost three electrons and only has 10. Thus, you should write the electron configuration for 10 electrons. This means you must eliminate the 3s23p1 shells. Answer: Al3+:1s22s22p6 or simply [Ne], which is a noble gas. This makes sense, as we know that the the Al3+ ion is stable.

Which of the following is the correct sequence for increasing order (i.e., smallest to largest) of first ionization energy (IE)? Be<B<N<O B<Be<O<N B<Be<N<O N<O<Be<B

B<Be<O<N Atoms with half-filled or completely filled orbitals in the outer shell are more stable and possess higher IE. As atomic radius increases, IE decreases. Although B is smaller than Be, we expect the Be atom to have a higher IE because of the stable 2s2 configuration. N's 1s22s22p3 configuration is more stable than the 1s22s22p4 configuration of O, so N has a greater IE than O

Which ion is isoelectronic with xenon?

Ba^2+

[The] _______states that the lowest-energy configuration for an atom with electrons within a set of degenerate orbitals is that having the maximum number of unpaired electrons.

Hund's rule

Which of the following elements has the lowest first ionization energy? Na K Mg Ca

K Potassium is the closest to the lowest left corner of the periodic table, so it is the largest atom and has only one valence electron. This makes it easiest to ionize.

Which of the following species is expected to have the smallest radius? S2− Cl− Ar K+

K bc bigger atomic number

Hund's rule states that the electron configuration with the lowest-energy will have the maximum possible number of unpaired electrons. Which of the elements below would require special attention to this rule to correctly depict the orbital diagram? H He N Be

N

Which ion is isoelectronic with krypton?

Rb+

Identify the element from the electron configuration: [Ar]4s^23d^2.

Ti Since there are additional electrons after the nobel gas, argon, we know that this element must be from period 4.

Which of the following causes a decrease in the effective nuclear charge felt by the valence electrons?

addition of an electron to the valence shell to form an anion.

For the purposes of determining electron configuration of ions, when electrons are added to a neutral atom, they will inhabit orbitals according to: the Pauli exclusion principle the Aufbau principle Hund's rule all of the above

all of the above

Valence electrons: (Select all that apply) are in the highest energy level. are not involved in bonding. participate in the formation of chemical bonding. occupy the inner shell orbitals.

are in the highest energy level. participate in the formation of chemical bonding.

Elements that have similar electron configurations belong to the same:

group

francium is the easiest to ionize while

helium is the hardest

For elements in the d block, the first electron removed will be a(n):

s electron

Cations have __________ radii than their neutral atoms, and anions have __________ radii than their neutral atoms.

smaller, larger Cations are smaller than their neutral atoms because losing electrons causes the radius to contract. Anions are larger than their neutral atoms because gaining electrons causes the radius to expand.

Which of the following can be used to show the spin state of an unpaired electron in an orbital? No spin Spin up Spin down Electrons are always paired.

spin up and spin down

Hund's Rule

states that orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron and that each of the single electrons must have the same spin

Degenerate is the word we use to refer to orbitals that have identical energy,

such as the orbitals inhabiting the same subshell

The Aufbau principle states

that an electron occupies orbitals in order from lowest energy to highest

The order in which orbitals are listed on an orbital diagram follows:

the Aufbau principle

An especially large increase in ionization energy occurs when __________.

the next electron to be removed is a core electron

Which of the following results in an increase in effective nuclear charge per electron?

the removal of electrons from the valence shell

electronic configuration

to represent the organization of electrons in shells and subshells in an atom

Which of the following has the last electron placed in a d orbital?

transition elements

Generally, on the periodic table, ionization energy increases __________.

up and right