Elements, Atoms, Shells, Subshells And Orbitals

Summary

In this educational video, Sahar explores the fundamental building blocks of matter: elements, atoms, shells, subshells, and orbitals. She explains how elements, of which 118 are known, form the basis of all matter on Earth, existing in gas, liquid, or solid states. The video delves into atomic structure, highlighting protons, neutrons, and electrons, and uses helium as an example to illustrate atomic mass and number. It further explains isotopes and radioisotopes, the arrangement of electrons in shells and subshells, and the significance of valence electrons in determining an element's chemical properties. The video concludes with a look at electronic configurations of various elements, emphasizing the role of outermost electrons in chemical bonding.

Takeaways

• 🌐 Everything on Earth, both living and non-living, is composed of elements, with 118 elements discovered to date.
• 🌡 Elements can exist in different states (gas, liquid, or solid) depending on the proximity of their particles.
• 🔬 Atoms, the building blocks of elements, consist of electrons, protons, and neutrons, with electrons having a negative charge, protons a positive charge, and neutrons being neutral.
• 💠 The atomic mass of an element is the sum of protons and neutrons, while the atomic number is the count of protons, which defines the element.
• 🔄 Isotopes are variants of an element with different numbers of neutrons, with some isotopes being unstable and radioactive, known as radioisotopes.
• 🌀 Electrons in an atom occupy shells and subshells, which are categorized as s, p, d, and f, with each type having a specific number of orbitals.
• 📊 The number of electrons that can fill each shell follows the 2n^2 rule, where n is the principal quantum number, determining the shell's capacity.
• 🔵 The electronic configuration of an atom describes how electrons are distributed across shells and subshells, dictating the atom's chemical properties.
• 🌟 The outermost shell, known as the valence shell, and its electrons, called valence electrons, significantly influence an element's chemical reactivity and bonding behavior.
• 🔬 The video provides a comprehensive overview of atomic structure, including the roles of shells, subshells, and orbitals in determining an element's properties.

Q & A

What are the three different states in which elements can exist?

Elements can exist in the form of gas, liquid, or solid state, depending on the particles present within these elements and their proximity to each other.

How many elements have been discovered so far?

Up till now, 118 elements have been discovered.

What are the three particles that make up an atom?

An atom is made up of electrons, protons, and neutrons. Electrons have a negative charge, protons have a positive charge, and neutrons have no charge.

What is the atomic mass of helium and how is it calculated?

The atomic mass of helium is 4, which is calculated by adding the number of protons and neutrons in the nucleus, with helium having 2 protons and 2 neutrons.

What is the difference between an isotope and a radioisotope?

Isotopes are variants of an element with different numbers of neutrons. Radioisotopes are unstable isotopes that release radiation to stabilize themselves, resulting from the decay of the nucleus.

How many electrons can the first shell of an atom accommodate?

The first shell of an atom can accommodate up to two electrons.

What are the different subshells found in the shells of an atom?

The different subshells found in the shells of an atom are s, p, d, and f subshells.

How many types of orbitals are there in a p subshell?

There are three different types of orbitals in a p subshell, which are 2px, 2py, and 2pz, corresponding to their movement along the x, y, and z axes.

What is the electronic configuration of hydrogen and helium?

The electronic configuration of hydrogen is 1s, and for helium, it is 1s2, indicating two electrons moving in opposite directions in the 1s subshell.

What is the significance of the valence shell in determining an element's chemical properties?

The valence shell, or the outermost shell, plays a crucial role in determining an element's chemical properties because it is the shell that participates in chemical bonding and reactions.

How do the chemical properties of lithium and sodium relate to their electronic configurations?

Lithium and sodium have similar chemical properties because they both have one electron in their outermost or valence shell, which is responsible for their reactivity and bonding characteristics.