Question

(a) True or false: The hydrogen atom is most stable when it has a full octet of electrons. (b) How many electrons must a sulfur atom gain to achieve an octet in its valence shell? (c) If an atom has the electron configuration \(1 s^{2} 2 s^{2} 2 p^{3},\) how many electrons must it gain to achieve an octet?

Short answer

(a) False, the hydrogen atom is stable with only 2 electrons in its 1s orbital. (b) A sulfur atom must gain 2 electrons to achieve an octet in its valence shell. (c) The atom with the given electron configuration, \(1s^{2}2s^{2}2p^{3}\), must gain 3 electrons to achieve an octet in its valence shell.

Step-by-step solution

Determine the stability of a hydrogen atom

The statement claims that the hydrogen atom is most stable when it has a full octet of electrons. However, the hydrogen atom needs only two electrons in its 1s orbital to achieve a stable electron configuration, as it has only one electron shell (the first shell) which can hold a maximum of just 2 electrons. Therefore, the statement is false. #b#

Determining the number of electrons a sulfur atom needs to gain for an octet

To find out how many electrons a sulfur atom must gain to achieve an octet in its valence shell, we must first understand its electron configuration. Sulfur is in Group 16 of the periodic table, which means it has six valence electrons (the electron configuration of sulfur is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{4}\)). To achieve an octet, sulfur needs to have a total of eight valence electrons. By subtracting its current number of valence electrons (6) from the desired octet (8), we find out that sulfur must gain 2 electrons.

Answer for part (b)

So, a sulfur atom must gain 2 electrons to achieve an octet in its valence shell. #c#

Determining the number of electrons an atom needs to gain for an octet given an electron configuration

The given electron configuration for the atom is \(1s^{2}2s^{2}2p^{3}\). The valence shell is the last shell with electrons and in this case, it is the second shell (2s and 2p orbitals). The second shell can hold a maximum of 8 electrons.

Calculate missing electrons to achieve an octet

By summing the electrons present in the second shell (2 + 3 = 5) and comparing it against the desired octet (8), we can calculate the number of electrons needed to achieve an octet: 8 - 5 = 3.

Answer for part (c)

Therefore, the atom with the given electron configuration must gain 3 electrons to achieve an octet in its valence shell.