Question

Refer to the periodic table and state the highest energy sublevel for each of the following elements: (a) H (b) \(\mathrm{Na}\) (c) Sm (d) Br (e) Sr (f) \(C\) (g) Sn (h) Cs

Short answer

(a) 1s; (b) 3s; (c) 4f; (d) 4p; (e) 5s; (f) 2p; (g) 5p; (h) 6s.

Step-by-step solution

Understand Energy Sublevels

In an atom, electrons are found in different sublevels based on their energy. These are designated as s, p, d, and f. The sequence of increasing energy for sublevels is: s < p < d < f.

Identify Sublevels by Element Group

The periodic table is arranged such that each group (or column) corresponds to a specific sublevel block. Elements in the \(s\)-block have their highest electrons in the s sublevel, \(p\)-block elements in the p sublevel, \(d\)-block in the d sublevel, and \(f\)-block in the f sublevel. Elements' valence electron configuration and highest sublevel reflect these blocks.

Apply to Each Element

Determine the highest energy sublevel for each element:(a) H: Located in the 1st row, it's in the s block, highest sublevel is 1s.(b) \(\mathrm{Na}\): Found in the s block, 3rd row, highest sublevel is 3s.(c) Sm: Located in the f block, specifically the lanthanide series, highest sublevel is 4f.(d) Br: In the p block, 4th row, highest sublevel is 4p.(e) Sr: Located in the s block, 5th row, highest sublevel is 5s.(f) \(C\): Found in the p block, 2nd row, highest sublevel is 2p.(g) Sn: In the p block, 5th row, highest sublevel is 5p.(h) Cs: Located in the s block, 6th row, highest sublevel is 6s.

Key concepts

Periodic Table

The periodic table is a systematic arrangement of all known chemical elements, and it plays a crucial role in organizing these elements based on their properties. Each element is placed in order of increasing atomic number, which represents the number of protons in the atom's nucleus. The table is structured into rows called periods and columns called groups.

• Elements in the same group share similar chemical behaviors because of having the same number of valence electrons.
• Periods correspond to the number of electron shells used by the elements in that row.

One important aspect of the periodic table is its division into blocks: the s-block, p-block, d-block, and f-block. This classification is based on the electron configuration of the elements, specifically the type of atomic orbital that receives the electron last.

Energy Sublevels

Within an atom, electrons are placed in orbitals and these orbitals are organized into energy sublevels. Each energy level has sublevels designated by different types of orbitals: s, p, d, and f. These sublevels have distinct shapes and capacities for holding electrons, and they fill in a specific order.

• The order of filling starts from 's' and continues to 'p', 'd', and then 'f'.
• S sublevel can hold up to 2 electrons, p can hold 6, d can hold 10, and f can accommodate 14.

This arrangement helps us understand why atoms behave the way they do chemically, and how they bond with other atoms. The sequence of filling allows elements to be systematically placed in the periodic table, making it easier to predict and understand an element's chemical properties.

s block elements

The s block elements are located on the left side of the periodic table, including the first two groups, Group 1 (alkali metals) and Group 2 (alkaline earth metals) plus helium from Group 18. The highest energy electrons in these elements are found in s orbitals.

• They typically have one or two electrons in their outermost s sublevel.
• These elements are generally highly reactive, especially the alkali metals.

An example of an s-block element is hydrogen, which has a simple electron configuration of 1s¹. Sodium (\(\mathrm{Na}\)) has an electron configuration that ends in 3s¹, indicating its position in the s block. These elements showcase unique chemical properties due to their s sublevel electron arrangements.

p block elements

The p block elements are located on the right side of the periodic table, spanning the last six groups (13 to 18). They are characterized by having their highest energy electrons in a p orbital.

• This block contains a rich diversity of elements including nonmetals, metalloids, and post-transition metals.
• The p sublevel can accommodate a maximum of 6 electrons, making these elements highly varied in chemical properties.

Elements such as carbon (C) and bromine (Br) are classic examples of p-block elements. For instance, carbon, with an electron configuration ending in 2p², plays a fundamental role in organic chemistry, while bromine (4p⁵) is essential in many compounds. The presence of a partially filled p sublevel gives these elements a range of oxidation states and bonding capabilities.