Question

How many \(3 d\) electrons are in an atom of each element? (a) \(\mathrm{Fe}\) (b) \(\mathrm{Zn}\) (c) \(\mathrm{K}\) (d) As

Short answer

Fe has 6 3d electrons; Zn has 10 3d electrons; K has 0 3d electrons; As has 5 3d electrons.

Step-by-step solution

- Identify the Group and Period of Each Element

Using the Periodic Table, identify the group and period of each element as they help in determining the electron configuration.

- Determine the Electron Configuration

Write down the electron configuration for each element. This shows the distribution of electrons among the orbitals.

- Count the Number of 3d Electrons

From the electron configuration, count the number of electrons in the 3d subshell for each element to find the number of 3d electrons present.

Key concepts

3d Electrons

Understanding the concept of 3d electrons is fundamental in the study of chemistry and physics, particularly when discussing transition metals. The term '3d electrons' refers to electrons that reside in the third 'd' subshell of an atom's electron configuration. This subshell starts to fill with electrons after the 4s subshell according to the Aufbau principle, which is a basic guideline for predicting the order in which orbitals are filled.

For instance, iron (Fe) has 6 electrons in its 3d subshell, while zinc (Zn) has a filled 3d subshell with 10 electrons. Conversely, potassium (K) and arsenic (As) lack 3d electrons altogether, with potassium (K) having its outermost electron in the 4s orbital and arsenic (As) having its valence electrons in the 4s and 4p orbitals. Counting these electrons correctly requires knowledge of the atom’s position on the periodic table and its electron configuration.

Periodic Table

The periodic table is not just a chart but an invaluable tool for chemists to understand and predict the properties of elements. It is organized by atomic number and divided into periods (rows) and groups (columns). Each element has its unique position, which dictates its electron configuration and, therefore, its chemical behavior.

Groups in the periodic table often share similar properties; for instance, the Group 1 alkali metals all have one electron in their outer shell. The periodic table also helps in identifying the types of orbitals that are filled with electrons in an element. The table is arranged so that as you move across a period, each element has one more proton and is one electron fuller than the element before it. This arrangement is crucial when determining the number of 3d electrons, especially for transition metals—elements located in Groups 3 to 12 on the periodic table.

Atomic Structure

To delve into atomic structure is to understand the very building blocks of matter. At the center of an atom lies the nucleus, containing protons and neutrons. Surrounding the nucleus are electrons, which are arranged in energy levels or 'shells'. Each shell can be filled with a certain number of electrons before the excess electrons start populating the next shell.

The Subatomic Particles

• Protons: Positively charged particles in the nucleus defining the atomic number.
• Neutrons: Neutral particles that add mass to the nucleus.
• Electrons: Negatively charged particles that orbit the nucleus in various shells and subshells.

Atomic structure is key to understanding why different elements behave differently and is the basis for concepts like valency and bonding. These structures dictate the physical and chemical properties of elements, such as conductivity and reactivity.

Electron Orbital

The concept of an electron orbital is central to modern chemistry. Orbitals are regions within an atom where electrons are most likely to be found. Each orbital can hold a maximum of two electrons and is defined by its shape, size, and orientation. The most basic types of orbitals are s, p, d, and f.

Shapes and Capacities of Basic Orbitals:

• s-orbital: Spherical shape, holds 2 electrons.
• p-orbital: Dumbbell-shaped, holds up to 6 electrons across 3 orientations.
• d-orbital: Clover-shaped, holds up to 10 electrons across 5 orientations.
• f-orbital: Complex shape, holds up to 14 electrons across 7 orientations.

When visualizing electron orbitals, picture them as 'clouds' around the nucleus where electrons are likely to be found. Clearly understanding electron orbitals is essential when solving problems related to electron configuration, as they determine how electrons are distributed within an atom.