Ionization energy The sciences of physics and chemistry use different measures of ionization energy. In physics, the unit is the amount of energy required to remove a single electron from a single atom or molecule, expressed as electronvolts. In chemistry, the unit is the amount of energy required for all of the atoms in a mole of substance to lose one electron each: molar ionization energy or enthalpy, expressed as kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). Comparison of "E" of elements in the periodic table reveals two periodic trends: The latter trend results from the outer electron shell being
Ground substance smaller amount of ground substance compared to the fibrous material. The meaning of the term has evolved over time. Ground substance Ground substance is an amorphous gel-like substance in the extracellular space that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. Ground substance is active in the development, movement, and proliferation of tissues, as well as their metabolism. Additionally, cells use it for support, water storage, binding, and a medium for intercellular exchange (especially between blood cells and other types of cells). Ground substance provides lubrication for collagen fibers. The components