Question

in the spaces below, write and illustrate electron configurations for the next four elements: nitrogen, oxygen, fluorine, and neon. when you are finished, use the gizmo to check your work. correct any improper configurations.
nitrogen configuration: ________________________
oxygen configuration: ________________________
fluorine configuration: ________________________
neon configuration: ________________________

1. apply: atoms are most stable when their outermost shell is full. if their outermost shell is not full, atoms tend to gain, lose, or share electrons until the shell fills up. while doing this, atoms react and form chemical bonds with other atoms.

based on this, what can you infer about the reactivity of helium and neon? ________________________

1. think and discuss: select the periodic table tab, and look at the second row, or period, of the table. how does this row reflect the subshells of the second shell?

Explanation:

• Nitrogen: Nitrogen has an atomic number of 7. Using the Aufbau principle, electrons fill the \(1s\) orbital first (2 electrons), then the \(2s\) orbital (2 electrons), and then the \(2p\) orbital. According to Hund's rule, electrons in degenerate orbitals (the three \(2p\) orbitals) are filled singly first. So, the electron configuration is \(1s^{2}2s^{2}2p^{3}\).
• Oxygen: Oxygen has an atomic number of 8. After filling \(1s^{2}\) and \(2s^{2}\), for the \(2p\) orbitals, since we have 4 electrons in the \(2p\) sub - shell (after \(1s\) and \(2s\) are filled), one of the \(2p\) orbitals will have a pair of electrons. The electron configuration is \(1s^{2}2s^{2}2p^{4}\).
• Fluorine: Fluorine has an atomic number of 9. After \(1s^{2}\) and \(2s^{2}\), in the \(2p\) sub - shell, we have 5 electrons. So, the electron configuration is \(1s^{2}2s^{2}2p^{5}\).
• Neon: Neon has an atomic number of 10. After filling \(1s^{2}\) and \(2s^{2}\), the \(2p\) sub - shell is completely filled with 6 electrons. The electron configuration is \(1s^{2}2s^{2}2p^{6}\).
• Reactivity of Helium and Neon: Helium has a \(1s^{2}\) configuration (its only shell is full), and neon has a \(1s^{2}2s^{2}2p^{6}\) configuration (its outermost shell is full). Since atoms are most stable when their outermost shell is full, they do not tend to gain, lose, or share electrons easily. So, they are non - reactive (inert).
• Second row of the Periodic Table: The second shell has two sub - shells (\(2s\) and \(2p\)). The \(2s\) sub - shell can hold 2 electrons (corresponding to the first two elements in the second row: lithium (\(1s^{2}2s^{1}\)) and beryllium (\(1s^{2}2s^{2}\))). The \(2p\) sub - shell can hold 6 electrons (corresponding to the next six elements in the second row: boron (\(1s^{2}2s^{2}2p^{1}\)) to neon (\(1s^{2}2s^{2}2p^{6}\))).

Answer:

• Nitrogen configuration: \(1s^{2}2s^{2}2p^{3}\)
• Oxygen configuration: \(1s^{2}2s^{2}2p^{4}\)
• Fluorine configuration: \(1s^{2}2s^{2}2p^{5}\)
• Neon configuration: \(1s^{2}2s^{2}2p^{6}\)
• Helium and neon are non - reactive (inert) because their outermost electron shells are full.
• The second row of the periodic table reflects the \(2s\) (first 2 elements) and \(2p\) (next 6 elements) sub - shells of the second shell.