Question

Which of the following element will have same number of electrons in s-as well as p-type of orbitals? (a) \(\mathrm{Fe}(Z=26)\) (b) \(\operatorname{Mg}(Z=12)\) (c) \(\operatorname{Ne}(Z=10)\) (d) \(\operatorname{Ar}(Z=18)\)

Short answer

The element with the same number of electrons in s and p orbitals is \text{Ne} (Z=10).

Step-by-step solution

- Write down the electronic configurations

To determine the number of electrons in s and p orbitals, write down the electronic configurations for the given elements using their atomic numbers (Z).

- Analyze the electronic configurations

Identify the number of electrons in s and p orbitals in the outermost energy level for each of the given elements.

- Determine the element with equal s and p electrons

Compare the number of s and p electrons for each element to find the one with equal numbers in both types of orbitals.

Key concepts

Understanding Atomic Number

The atomic number, denoted by the letter Z, is fundamental to understanding an element's properties. It represents the number of protons found in the nucleus of an atom and, by extension, also indicates the total number of electrons in a neutral atom. For instance, if an element has an atomic number of 8, it means it has 8 protons and, consequently, 8 electrons.

Why is this important for electronic configurations? Because the atomic number directs us to how electrons are arranged around the nucleus. This arrangement, known as the electronic configuration, follows a set of rules based on quantum mechanics. Electrons fill lower energy orbitals first before moving to higher ones, starting with the 's' orbital and progressing to 'p', 'd', and 'f' orbitals.

Understanding atomic numbers allows us to predict the chemical behavior of an element, such as ionization energy, electronegativity, and the types of bonds it can form. This, in turn, is crucial when comparing elements and predicting how they will interact in chemical reactions.

Navigating s and p Orbitals

Electrons exist in areas around the nucleus called orbitals, with 's' and 'p' representing two types. The 's' orbital, which is spherical, can hold a maximum of 2 electrons. Elements with their outer electrons in an 's' orbital are said to be in an 's' block.

The 'p' orbitals are shaped like dumbbells and can accommodate a total of 6 electrons—2 electrons per each of the three 'p' orbitals. When the outer electrons of an element reside in 'p' orbitals, the element belongs to the 'p' block. These orbitals start filling up after the 's' orbital has been filled.

Importantly, the 's' and 'p' orbitals form the valence shell—the outermost electron shell of an atom that determines its bonding behavior. Knowing which orbitals are filled is key to understanding an element's reactivity and the types of molecules it can form.

Electron Configuration Analysis

Analyzing an element's electron configuration means deciphering the arrangement of electrons in orbitals. This analysis requires a clear understanding of the order in which orbitals are filled, as governed by the principles of quantum mechanics. The order, often simplified as '1s 2s 2p 3s 3p 4s 3d 4p', reveals the sequence by which different orbitals gain electrons.

To perform electron configuration analysis, use the atomic number to add electrons to the respective orbitals following the above sequence. For example, carbon, with an atomic number of 6, would have an electron configuration of '1s² 2s² 2p²', revealing 2 electrons in the 's' orbital and 2 in the 'p' orbital of its second energy level (valence shell).

Analyzing electron configurations helps us to determine the chemical and physical properties of an element, predict chemical bonding patterns, and understand the element's position in the periodic table. It is a cornerstone in the study of chemistry, enabling us to visualize the invisible structure of atoms.