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A fine powder of aluminium reacts explosively on contact with liquid oxygen; under normal conditions, however, aluminium forms a thin oxide layer (~5 nm at room temperature) [43] that protects the metal from further corrosion by oxygen, water, or dilute acid, a process termed passivation.
Matter organizes into various phases or states of matter depending on its constituents and external factors like pressure and temperature.Except at extreme temperatures and pressures, atoms form the three classical states of matter: solid, liquid and gas.
Matter in the solid state maintains a fixed volume (assuming no change in temperature or air pressure) and shape, with component particles (atoms, molecules or ions) close together and fixed into place. Matter in the liquid state maintains a fixed volume (assuming no change in temperature or air pressure), but has a variable shape that adapts ...
Al 2 O commonly exists as a gas, since the solid state is not stable at room temperature and is only stable between 1050 and 1600 °C. Aluminium(I) oxide is formed by heating Al and Al 2 O 3 in a vacuum while in the presence of SiO 2 and C, and only by condensing the products. [2]
A Assuming an altitude of 194 metres above mean sea level (the worldwide median altitude of human habitation), an indoor temperature of 23 °C, a dewpoint of 9 °C (40.85% relative humidity), and 760 mmHg sea level–corrected barometric pressure (molar water vapor content = 1.16%). B Calculated values *Derived data by calculation.
Let d is a plate distance in meters, P is an air pressure in Pascals (N/m 2), T is temperature Kelvin, C is this Lasance constant 7.6 ⋅ 10 −5 m ⋅ K/N and PP is the product P ⋅ d/T. The Lasance approximation formula is K e /K 0 = 1/(1+C/PP) .
In the air, surface oxidation occurs above 700 °C (973 K; 1,292 °F), and even at room temperature, surface oxide layers of 5–10 nm thickness have been detected. This oxide layer protects the material up to 1,370 °C (1,640 K; 2,500 °F). Above this temperature bulk oxidation occurs.
At room temperature, AlX compounds tend to disproportionate to Al and AlX 3. When dark red, solid AlCl is allowed to warm up, it turns black to yield aluminium and the more stable aluminium (III) chloride salt. [1] () + Dohmier et al. documented that the exception is AlBr.