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Red phosphorus may be formed by heating white phosphorus to 250 °C (523 K) in the absence of air or by exposing it to sunlight. [13] In this form phosphorus is amorphous, but can be crystallised upon further heating into violet phosphorus or fibrous red phosphorus depending on the reaction conditions. Red phosphorus is therefore not an ...
Red phosphorus may be formed by heating white phosphorus to 300 °C (570 °F) in the absence of air or by exposing white phosphorus to sunlight. Red phosphorus exists as an amorphous network. Upon further heating, the amorphous red phosphorus crystallizes. It has two crystalline forms: violet phosphorus and fibrous red phosphorus. Bulk red ...
Under standard conditions, red phosphorus is more stable than white phosphorus, but less stable than the thermodynamically stable black phosphorus. The standard enthalpy of formation of red phosphorus is −17.6 kJ/mol. [3] Red phosphorus is kinetically most stable. Being polymeric, red phosphorus is insoluble in solvents. It shows ...
Perlite, a porous white volcanic rock that improves drainage and aeration. Slow-release fertilizer is sometimes added to potting mixes. It looks like tiny, round balls and lasts a few months.
Highly oxidized red soil in Tirunelveli District, India. Red colors often indicate iron accumulation or oxidation in oxygen-rich, well-aerated soils. [4] Iron concentrations caused by redox reactions because of diffusion of iron in crystalline and metermorphic rock, in periodically saturated soils may also present red colors, particularly along root channels or pores.
Soil heat flux refers to the rate at which heat energy moves through the soil in response to a temperature difference between two points in the soil. The heat flux density is the amount of energy that flows through soil per unit area per unit time and has both magnitude and direction.
Nutrients in the soil are taken up by the plant through its roots, and in particular its root hairs.To be taken up by a plant, a nutrient element must be located near the root surface; however, the supply of nutrients in contact with the root is rapidly depleted within a distance of ca. 2 mm. [14] There are three basic mechanisms whereby nutrient ions dissolved in the soil solution are brought ...
Additionally, some bacteria can fix atmospheric nitrogen, and some fungi are efficient at extracting deep soil phosphorus and increasing soil carbon levels in the form of glomalin. [69] Plants hold soil against erosion, and accumulated plant material build soil humus levels. Plant root exudation supports microbial activity.