Problem 36 Write the electron configuration... [FREE SOLUTION] (2024)

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Electron configuration is a representation of the arrangement of electrons in an atom's orbitals, which are regions around the nucleus where electrons are likely to be found. These configurations are written using a shorthand notation that lists the orbitals and the number of electrons they contain. For example, neon has an atomic number of 10, meaning it has 10 electrons. Its electron configuration is written as 1s² 2s² 2p⁶. Here, '1s²' indicates that the first energy level's 's' orbital contains two electrons. The '2s²' signifies a similar situation for the second energy level's 's' orbital. Lastly, '2p⁶' denotes that the second energy level's 'p' orbital is filled with six electrons, completing the octet rule for stability. Understanding electron configuration is fundamental in studying chemistry as it reveals useful information about an element's reactivity and the types of bonds it can form.

When trying to grasp the concept of electron configuration, it can be helpful to visualize the orbitals as 'containers' for electrons, with each container having a specified capacity. The '1s' orbital has a maximum capacity of two electrons, as does each '2s' orbital. A 'p' orbital can hold up to six electrons. Following the 'Aufbau principle', electrons fill the lowest energy orbitals first before moving to higher ones, much like filling cups with water from the bottom shelf upward to avoid spilling.

Valence electrons play a central role in chemical reactivity and bonding because they are the electrons located in an atom's outermost shell. They are the 'workers' of the atom when it comes to forming bonds with other atoms. For neon, which has an electron configuration of 1s² 2s² 2p⁶, the valence electrons are the ones in the 2s and 2p orbitals. Since the 's' and 'p' orbitals of the second energy level (also known as the n=2 shell) are fully occupied, neon has eight valence electrons.

To determine the number of valence electrons in other elements, a quick look at the periodic table can help. Elements in the same group (vertical column) typically have the same number of valence electrons. For instance, all noble gases like neon, located in the last group, have complete valence electron shells, contributing to their well-known chemical inertness. Recognizing the significance of valence electrons is key to predicting how an element might interact and what type of bonds it will form.

The periodic table is the roadmap for understanding all the known chemical elements. It is an organized chart where elements are arranged in order of increasing atomic number, which is the number of protons in the nucleus of an atom. The table is also structured into periods (horizontal rows) and groups (vertical columns), where elements in the same period have the same number of atomic orbitals and elements in the same group have similar chemical properties, generally due to having the same number of valence electrons.

By using the table, students can identify relationships between elements, predict the types of chemical reactions that might occur, and understand the trends in properties like electronegativity, atomic radius, and ionization energy. For instance, neon is placed in period 2 as it has two principal energy levels, and in group 18, known as noble gases, elements which are all characterized by having full valence electron shells and being mostly non-reactive. Learning to navigate the periodic table is like learning to read a map, revealing the landscape of elements' physical and chemical properties.

The atomic number is a fundamental property of an element as it defines the identity of the element. It is equal to the number of protons found within the nucleus of an atom and, by extension, when the atom is neutrally charged, it is also equal to the number of electrons around the nucleus. The periodic table is arranged by ascending atomic numbers. The atomic number of neon is 10, which not only informs us that it has 10 protons and 10 electrons but also places it unequivocally in the periodic table.

An element's atomic number is a quick guide to many of its properties and is relatively easy to remember. Furthermore, the concepts of atomic number and electron configuration are closely linked; as you move across the periodic table, each subsequent element has an additional proton and an additional electron, which leads to changes in electron configuration. It's important for students to distinguish atomic number from other numbers like atomic mass, which includes the count of protons and neutrons — both essentials in understanding chemical behavior and the subtleties of the periodic table.