Using the periodic table to locate each element, write the electron configuration of (a) \(\mathrm{V} ;\) (b) \(\mathrm{Y} ;\) (c) \(\mathrm{Hg}\).

The Aufbau principle is a rule used to determine the electron configuration of an atom. It states that electrons fill orbitals starting from the lowest energy level to the highest. This means that electrons will start filling the 1s orbital before moving to the 2s orbital and so on.

The order in which orbitals are filled is not always straightforward because some orbitals overlap in energy levels. For example, the 4s orbital is filled before the 3d orbital. Remember, electrons always occupy the lowest available energy orbital, moving upwards as they fill up.

• Lowest energy orbitals are filled first
• Electrons occupy orbitals in a way that minimizes the energy of the atom
• Order of orbitals: 1s, 2s, 2p, 3s, 3p, 4s, 3d, etc.

Understanding this principle makes it easier to write the electron configurations for elements, ensuring that electrons are placed in the correct orbitals.

The periodic table is an essential tool for understanding the properties and the electron configurations of elements. By knowing an element's location on the periodic table, you can determine its atomic number, its electron configuration, and its chemical properties.

Each element is positioned in a specific column called a 'group', and a row called a 'period'. Group numbers help predict the number of valence electrons, which in turn determine the chemical reactivity of the element. Period numbers indicate the energy levels that are being filled. For example, elements in the fourth period have electrons filling up to the 4th energy level.

• Group: Vertical columns (elements with similar properties)
• Period: Horizontal rows (indicates the highest energy level being filled)
• Key to find atomic number and electron configuration

Using the periodic table helps simplify the process of determining electron configurations through a structured approach.

The atomic number of an element is a critical piece of information when determining its electron configuration. It represents the number of protons in an atom's nucleus and, for neutral atoms, it also equals the number of electrons.

The atomic number increases as you move from left to right on the periodic table. Elements are arranged in ascending order of their atomic numbers. This number essentially tells us how many electrons need to be assigned to an element's orbitals following the Aufbau principle.

• Represents number of protons and electrons in a neutral atom
• Increases from left to right across the periodic table
• Important for writing correct electron configurations

Knowing the atomic number allows you to quickly locate the correct position of an element on the periodic table and determine the electron configuration using the rules stated earlier.

Orbitals are regions around an atom's nucleus where electrons are likely to be found. These are essential for understanding the organization of electrons within an atom. Each type of orbital has a different shape and can hold a specific number of electrons: s-orbitals hold 2, p-orbitals hold 6, d-orbitals hold 10, and f-orbitals hold 14 electrons.

Orbitals are filled in a specific sequence dictated by their energy levels, thanks to the Aufbau principle. The shapes and orientations of orbitals also determine how atoms interact when forming chemical bonds.

• s-orbital: Spherical shape, holds 2 electrons
• p-orbital: Dumbbell shape, holds 6 electrons
• d-orbital: Complex shape, holds 10 electrons
• f-orbital: Even more complex shape, holds 14 electrons

Having a deep understanding of orbitals is crucial for grasping more advanced concepts in chemistry, such as bonding and molecular geometry.