Which atom in the ground state contains only one completely filled p orbital?
(1) Ne
(2) O
(3) He
(4) Be
Answer (2)
Determine the electron configuration of each atom.
Identify the atom with only one completely filled p orbital.
Neon (Ne) has the electron configuration 1 s 2 2 s 2 2 p 6 , which has one completely filled p orbital.
Therefore, the answer is N e .
Explanation
Problem Analysis The question asks us to identify which atom, in its ground state electron configuration, possesses only one completely filled p orbital. A completely filled p orbital contains 6 electrons. We will examine the electron configurations of the given options to determine the correct answer.
Analyzing Each Option Let's analyze each option:
(1) Neon (Ne): Neon has an atomic number of 10. Its electron configuration is 1 s 2 2 s 2 2 p 6 . The 2 p orbital is completely filled, and it is the only p orbital present. Thus, Neon has only one completely filled p orbital.
(2) Oxygen (O): Oxygen has an atomic number of 8. Its electron configuration is 1 s 2 2 s 2 2 p 4 . The 2 p orbital is not completely filled.
(3) Helium (He): Helium has an atomic number of 2. Its electron configuration is 1 s 2 . Helium does not have any p orbitals.
(4) Beryllium (Be): Beryllium has an atomic number of 4. Its electron configuration is 1 s 2 2 s 2 . Beryllium does not have any p orbitals.
Conclusion Based on the electron configurations, only Neon (Ne) has one completely filled p orbital.
Examples
Understanding electron configurations helps us predict how atoms will interact to form chemical bonds. For example, knowing that Neon has a completely filled p orbital explains why it is a noble gas and is very unreactive. This concept is crucial in understanding chemical reactivity and the formation of molecules.
The atom that contains only one completely filled p orbital in its ground state is Neon (Ne), which has an electron configuration of 1 s 2 2 s 2 2 p 6 . This means its 2p orbital is completely filled with 6 electrons. Therefore, the answer is (1) Ne.
;
