Identifying the “cheapest” element is more intricate than simply pinpointing a single chemical substance. Its cost is influenced by natural prevalence, ease of extraction, and industrial demand. True affordability considers how readily an element can be obtained and utilized in practical applications, extending beyond a simple measure of its presence.
Understanding Element Cost
Defining an element as “cheapest” depends on its universal abundance, terrestrial abundance, or market price. Hydrogen is the most abundant element in the universe, making up approximately 75% of its elemental mass. On Earth, oxygen is the most abundant element in the crust (46% by weight), and nitrogen makes up about 78% of the atmosphere by volume.
For industrial applications, elements like hydrogen, oxygen, nitrogen, and carbon are considered inexpensive. Their widespread presence in accessible forms, such as air and water, contributes to their lower cost. Unlike rare elements that require complex mining or synthesis, these are readily available as raw materials for large-scale production. The “cheapest” elements are thus terrestrially abundant and economically viable to extract and process for various uses.
Why Some Elements Are Inexpensive
The low cost of certain elements stems from their widespread natural occurrence and the simplicity of their industrial processing. Hydrogen, as the lightest and most abundant element in the universe, is a fundamental component of water and hydrocarbons, which are readily available on Earth. Oxygen and nitrogen are primary constituents of Earth’s atmosphere. Carbon is also highly abundant, forming the backbone of all organic matter and existing in vast reserves as fossil fuels.
The ease of extraction and purification plays a significant role in keeping costs down. Oxygen and nitrogen are separated from air using methods like cryogenic distillation or pressure swing adsorption (PSA). Hydrogen is produced through steam-methane reforming or electrolysis. These processes are well-established and can be scaled up to meet high industrial demand.
High demand for these elements drives down their per-unit cost through economies of scale. For instance, the extensive need for oxygen in medical applications and industrial processes, or nitrogen for fertilizers and inert atmospheres, encourages large-scale, efficient production facilities. Carbon’s omnipresence in fuels and materials means its various forms are continuously extracted and processed at massive scales, contributing to its affordability. The availability of abundant raw materials like air, water, and fossil fuels, combined with efficient, large-scale processing technologies, underpins the inexpensive nature of these elements.
Everyday Uses of Common Elements
The widespread availability and low cost of oxygen, nitrogen, hydrogen, and carbon make them essential in numerous everyday applications. Oxygen, a gas essential for life, is extensively used in medical facilities to support respiration and in various industrial processes, including welding, metal cutting, and wastewater treatment. Its role in combustion also makes it important for energy production.
Nitrogen, an abundant atmospheric gas, is important for agriculture as a primary component of fertilizers. In industrial settings, it creates inert atmospheres to prevent oxidation, safeguarding food products and sensitive materials. Its low reactivity makes it ideal for these protective applications.
Hydrogen is an important component in the production of ammonia for fertilizers and in refining petroleum products. It is increasingly explored as a clean energy carrier for fuel cells, which generate electricity with water as the only byproduct, offering a path toward sustainable transportation and power generation.
Carbon is essential to life and industry. It forms the basis of all fossil fuels like coal, oil, and natural gas, which are primary energy sources for power generation and transportation. Beyond energy, carbon is a building block for plastics, pharmaceuticals, and many construction materials, showcasing its important role in modern society.