Question 1

An element with the electron configuration [Xe] 6s²4f¹⁴5d⁷ would belong to which class on the periodic table? A)transition elements B)alkaline earth elements C)halogens D)rare earth elements E)none of the above

Accepted Answer

The electron configuration [Xe] 6s²4f¹⁴5d⁷ corresponds to an element in the transition metals, specifically in the 5d block, which are part of the transition elements.

Question 2

The complete electron configuration of tin is A)1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5d¹⁰5p² B)1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4d¹⁰4p² C)1s²2s²2p⁶3s²3p⁶4s²4p⁶5s²4d¹⁰5d¹⁰5p² D)1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p² E)none of these

Accepted Answer

The correct electron configuration for tin (Sn) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p².

Question 3

An atom of fluorine contains nine electrons.How many of these electrons are in s orbitals?
A)2
B)4
C)6
D)8
E)none

Accepted Answer

The answer of An atom of fluorine contains nine electrons.How...

Question 4

The electron configuration for the carbon atom is: A)1s²2s²2p² B)[He]2s⁴ C)[Ne]2s²2p² D)1s²2p⁴ E)none of these

Accepted Answer

Carbon has an atomic number of 6, so its electron configuration is 1s² 2s² 2p².

Question 5

Of the following elements,which needs three electrons to complete its valence shell?
A)Ba
B)Ca
C)Si
D)P
E)Cl

Accepted Answer

P has five valence electrons and needs three more to complete its valence shell, thus making it stable.

Question 6

Which of the following atoms has three electrons in p orbitals in its valence shell?
A)Ba
B)Ga
C)V
D)Bi
E)none of these

Accepted Answer

The answer of Which of the following atoms has three...

Question 7

Which of the following statements is false? A)An orbital can accommodate at most two electrons. B)The electron density at a point is proportional to $\varPsi$ ² at that point. C)The spin quantum number of an electron must be either + or - . D)A 2p orbital is more penetrating than a 2s;i.e. ,it has a higher electron density near the nucleus and inside the charge cloud of a 1s orbital. E)In the usual order of filling,the 6s orbital is filled before the 4f orbital.

Accepted Answer

The answer of Which of the following statements is false?
A)An...

Question 8

Fe has __________ that is (are)unpaired in its d orbitals.
A)one electron
B)two electrons
C)three electrons
D)four electrons
E)none of these

Accepted Answer

Iron (Fe) in its ground state has the electron configuration [Ar] 3d^6 4s^2. In the 3d subshell, there are four unpaired electrons.

Question 9

Which of the following statements is true? A)The exact location of an electron can be determined if we know its energy. B)An electron in a 2s orbital can have the same n,l,and m_l quantum numbers as an electron in a 3s orbital. C)Ni has two unpaired electrons in its 3d orbitals. D)In the buildup of atoms,electrons occupy the 4f orbitals before the 6s orbitals. E)Only three quantum numbers are needed to uniquely describe an electron.

Accepted Answer

The electron configuration of Ni is [Ar] 3d8 4s2, which means there are two unpaired electrons in the 3d orbitals, specifically in the 3d7 and 3d8 orbitals.

The other statements are false. A is false because of the Heisenberg uncertainty principle, which states that it is impossible to know the exact location and energy of an electron simultaneously. B is false because the principal quantum number (n) determines the energy level, and electrons in different energy levels cannot have the same quantum numbers. D is false because electrons occupy the 6s orbital before the 4f orbital in the buildup of atoms. E is false because four quantum numbers (n, l, mℓ, and mS) are needed to uniquely describe an electron.

Question 10

All alkaline earths have the following number of valence electrons:
A)1
B)3
C)6
D)2
E)none of these

Accepted Answer

Alkaline earths belong to group 2 of the periodic table, which means they have 2 valence electrons. Therefore, choice D (2) is the correct answer.

Question 11

Of the following elements,which has occupied d orbitals in its ground-state neutral atoms?
A)Ba
B)Ca
C)Si
D)P
E)Cl

Accepted Answer

Barium (Ba) is in the 6th period and has electrons in the 5d orbital in its ground-state electron configuration.

Question 12

Which of the following statements about quantum theory is incorrect?
A)The energy and position of an electron cannot be determined simultaneously.
B)Lower energy orbitals are filled with electrons before higher energy orbitals.
C)When filling orbitals of equal energy,two electrons will occupy the same orbital before filling a new orbital.
D)No two electrons can have the same four quantum numbers.
E)All of these are correct.

Accepted Answer

C) is incorrect because it misrepresents Hund's rule. According to Hund's rule, electrons fill degenerate orbitals singly first, with parallel spins, before pairing up in any one orbital.

Question 13

An element has the electron configuration [Kr] 5s²4d¹⁰5p².The element is a(n) A)nonmetal B)transition element C)metal D)lanthanide E)actinide

Accepted Answer

The presence of the electron configuration [Kr] 5s1 indicates that the element is a metal. The other electron configurations are consistent with a group 14 element, such as tin.

Question 14

Germanium has __________ in its 4p orbitals.
A)one electron
B)two electrons
C)three electrons
D)four electrons
E)none of these

Accepted Answer

The answer of Germanium has __________ in its 4p orbitals.
A)one...

Question 15

Which of the following electron configurations is correct? A)Ga: [Kr]4s²3d¹⁰4p¹ B)Mo: [Kr]5s²4d⁵ C)Ca: [Ar]4s¹3d¹⁰ D)Br: [Kr]4s²3d¹⁰4p⁷ E)Bi: [Xe]6s²4f¹⁴5d¹⁰6p³

Accepted Answer

The answer of Which of the following electron configurations is...

Question 16

Ti has __________ in its d orbitals.
A)one electron
B)two electrons
C)three electrons
D)four electrons
E)none of these

Accepted Answer

The electronic configuration of Ti is [Ar]3d24s2. The 3d orbital can hold a maximum of 10 electrons, but in Ti it contains only 2 electrons. Thus, Ti has 2 electrons in its d orbitals, which is represented by option B.

Question 17

The electron configuration for the barium atom is: A)1s²2s²2p⁶3s²3p⁶4s²3d¹⁰ B)[Xe]6s² C)1s²2s²2p⁶3s²3p⁶4s¹ D)1s²2s²2p⁶3s²3p⁶4s² E)none of these

Accepted Answer

The electron configuration for barium is obtained by filling electrons in the subshells in order of increasing energy. Starting from the 1s orbital, the electrons are filled in a specific order, filling the 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, and 6p orbitals in that order. Therefore, the configuration for barium is [Xe]6s2.

Question 18

An element E has the electron configuration [Kr] 5s²4d¹⁰5p².The formula for the fluoride of E is most likely A)EF₁₄ B)EF₄ C)EF D)EF₆ E)EF₈

Accepted Answer

The given electron configuration is a cipher for [Kr] 5s^2 4d^10 5p^5, which corresponds to the element iodine (I). Iodine typically forms a -1 anion when it reacts with fluorine, leading to the formation of IF_5, which matches choice B when decoded.

Question 19

The statement that "the lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of degenerate orbitals" is known as
A)the aufbau principle
B)Hund's rule
C)Heisenberg uncertainty principle
D)the Pauli exclusion principle
E)the quantum model

Accepted Answer

Hund's rule states that the lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of degenerate orbitals. The aufbau principle is the idea that electrons fill atomic orbitals in order of increasing energy levels. The Pauli exclusion principle states that no two electrons in an atom can have the same four quantum numbers. The Heisenberg uncertainty principle states that it is impossible to simultaneously determine the exact position and momentum of a particle. The quantum model is an updated model of the atom that takes into account quantum mechanics.

Question 20

How many unpaired electrons are there in an atom of sulfur in its ground state?
A)0
B)1
C)2
D)3
E)4

Accepted Answer

The answer of How many unpaired electrons are there in...

Quiz 7: Atomic Structure and Periodicity

An element with the electron configuration [Xe] 6s²4f¹⁴5d⁷ would belong to which class on the periodic table?

The complete electron configuration of tin is

An atom of fluorine contains nine electrons.How many of these electrons are in s orbitals?

The electron configuration for the carbon atom is:

Of the following elements,which needs three electrons to complete its valence shell?

Which of the following atoms has three electrons in p orbitals in its valence shell?

Which of the following statements is false?

Fe has __________ that is (are) unpaired in its d orbitals.

Which of the following statements is true?

All alkaline earths have the following number of valence electrons:

Of the following elements,which has occupied d orbitals in its ground-state neutral atoms?

Which of the following statements about quantum theory is incorrect?

An element has the electron configuration [Kr] 5s²4d¹⁰5p².The element is a(n)

Germanium has __________ in its 4p orbitals.

Which of the following electron configurations is correct?

Ti has __________ in its d orbitals.

The electron configuration for the barium atom is:

An element E has the electron configuration [Kr] 5s²4d¹⁰5p².The formula for the fluoride of E is most likely

The statement that "the lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of degenerate orbitals" is known as

How many unpaired electrons are there in an atom of sulfur in its ground state?