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About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life.
Humans obtain energy from three classes of fuel molecules: carbohydrates, lipids, and proteins. The potential chemical energy of these molecules is transformed into other forms, such as thermal...
12 Σεπ 2024 · chemical energy, Energy stored in the bonds of chemical compounds. Chemical energy may be released during a chemical reaction, often in the form of heat; such reactions are called exothermic. Reactions that require an input of heat to proceed may store some of that energy as chemical energy in newly formed bonds.
23 Σεπ 2024 · What is energy? What is the unit of measurement for energy? Can energy be created? energy, in physics, the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. There are, moreover, heat and work—i.e., energy in the process of transfer from one body to another.
Chemical energy is potential energy stored in chemical bonds in electrostatic potential energy. Gravitation potential energy is due to position or height relative to the earth. The earth attracts other objects with force \( F = mg\), where F is the force, m is the object's mass, and g is the acceleration due to gravity.
In the context of chemistry, energy is an attribute of a substance as a consequence of its atomic, molecular, or aggregate structure. Since a chemical transformation is accompanied by a change in one or more of these kinds of structure, it is usually accompanied by a decrease, and sometimes an increase, of the total energy of the substances ...
The human body is made of atoms. Air and water are made of atoms, too. Atoms are so small that millions of them would fit on the head of a pin. Atoms are made of even smaller particles. The center of an atom is called the nucleus. The nucleus is made up of particles called protons and neutrons. Electrons spin around the nucleus in shells.
