Oxygen

Definition

Oxygen is a highly reactive nonmetallic element that is essential for most forms of life. It is the third most abundant element in the universe and the most abundant element on Earth's crust. Oxygen plays a crucial role in various chemical and biological processes, including respiration, combustion, and oxidation-reduction reactions.

5 Must Know Facts For Your Next Test

1. Oxygen was discovered in the 1770s by Carl Wilhelm Scheele and Joseph Priestley, and its role in combustion and respiration was later established.
2. Oxygen is the most abundant element in the Earth's crust, making up about 46% of its mass, and is the second most abundant element in the atmosphere at 20.9% by volume.
3. Oxygen is essential for cellular respiration, where it is used to convert the chemical energy in food into a form that cells can use, known as ATP.
4. Oxygen is a key component in the formation of ozone (O$_3$) in the upper atmosphere, which helps protect the Earth from harmful ultraviolet radiation.
5. Oxygen can form a wide range of compounds, including oxides, peroxides, and superoxides, which play important roles in various chemical and biological processes.

Review Questions

• Explain the role of oxygen in the periodic table and its significance in early atomic theory.
  • Oxygen is a key element in the periodic table, belonging to the chalcogen group (group 16) and having an atomic number of 8. In the context of early atomic theory, oxygen was instrumental in the development of the concept of chemical elements and the understanding of the composition of compounds. Lavoisier's experiments with oxygen helped establish the role of this element in combustion and respiration, which were crucial in the formulation of the modern atomic theory.
• Describe how the periodic properties of oxygen, such as electronegativity and atomic radius, influence its chemical behavior and ability to form covalent bonds.
  • Oxygen has a high electronegativity, which means it has a strong tendency to attract electrons and form covalent bonds. This property, combined with its small atomic radius, allows oxygen to form multiple bonds with other elements, including the formation of double and triple bonds. These bonding characteristics of oxygen are essential in understanding its role in various chemical reactions, such as the formation of water, carbon dioxide, and other important compounds, as well as its participation in oxidation-reduction processes.
• Analyze the significance of oxygen in the context of stoichiometry, gas laws, and the mole concept, and how these principles are applied in the study of oxygen-containing substances and their reactions.
  • Oxygen is a key element in the study of stoichiometry, gas laws, and the mole concept. The molar mass of oxygen is used in the calculation of formula masses and the determination of empirical and molecular formulas. Additionally, the behavior of oxygen-containing gases, such as oxygen gas and carbon dioxide, is governed by the gas laws, which are essential in understanding the stoichiometry of gaseous reactions involving oxygen. The ability to quantify the amount of oxygen in a reaction, using the mole concept, is crucial in analyzing the reactivity and products of oxygen-based chemical processes, including combustion, respiration, and corrosion.

Related terms

Oxidation:

A chemical reaction in which an element or compound loses electrons, typically involving the addition of oxygen or the removal of hydrogen.

Ozone:

A highly reactive allotrope of oxygen, composed of three oxygen atoms, that forms a protective layer in the upper atmosphere.

Combustion:

A chemical reaction that occurs between a fuel and an oxidizing agent, such as oxygen, resulting in the release of heat and the formation of new products.