Question

The element with electronic configuration \(1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{6}\) \(3 \mathrm{~s}^{2}\) is (1) metalloid (2) metal (3) noblc gas (4) non-mctal

Short answer

The element is a metal.

Step-by-step solution

- Identify the element

The given electronic configuration is \(1s^2 2s^2 2p^6 3s^2\). Count the total number of electrons: 2 (from 1s) + 2 (from 2s) + 6 (from 2p) + 2 (from 3s) = 12. Therefore, the element has atomic number 12, which corresponds to Magnesium (Mg).

- Determine the nature of the element

Magnesium (Mg), with atomic number 12, is known to be a metal. Metals are located on the left side and center of the periodic table.

Key concepts

Atomic Number

The atomic number is a fundamental property of an element. It represents the number of protons in the nucleus of an atom. For neutral atoms, the number of protons also equals the number of electrons. This means the atomic number tells us how many electrons an atom has.
In the given exercise, we have the electronic configuration, which helps us count the total electrons to find the atomic number.
For instance, the configuration 1s² 2s² 2p⁶ 3s² yields a sum of 12 electrons. Therefore, the atomic number is 12.

Element Classification

Elements can be classified based on their properties, such as metals, non-metals, metalloids, and noble gases.

• Metals: Conduct electricity, shiny, and are malleable. They are usually on the left and center of the periodic table.
• Non-metals: Poor conductors of electricity, not shiny, and brittle. They are found on the right side of the periodic table.
• Metalloids: Have properties in between metals and non-metals and are found along the 'staircase' line on the periodic table.
• Noble gases: Inert and non-reactive due to full valence electron shells. They are located in Group 18 of the periodic table.

Knowing the element's classification helps us understand its chemical behavior and physical properties. In the exercise, Magnesium, with atomic number 12, is a metal.

Periodic Table

The periodic table is an organized chart of elements based on atomic number, electron configurations, and recurring chemical properties. Each element is placed in a specific location according to its atomic structure.
The table has rows called periods and columns called groups or families.

• Vertical columns (groups) indicate elements with similar chemical behaviors.
• Horizontal rows (periods) show elements with the same number of electron shells.

In the periodic table, metals are found on the left and center, non-metals are on the right, and metalloids are situated between metals and non-meals, making a zigzag line. The periodic table helps us visually understand relationships and predict chemical reactions.
For instance, Magnesium is in Group 2 and Period 3, emphasizing similar properties with other Group 2 elements like Calcium and Barium.