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Lead(IV) oxide, commonly known as lead dioxide, is an inorganic compound with the chemical formula PbO 2.It is an oxide where lead is in an oxidation state of +4. [1] It is a dark-brown solid which is insoluble in water. [2]
Scrutinyite / ˈ s k r uː t ɪ n i. aɪ t / is a rare oxide mineral and is the alpha crystalline form of lead dioxide (α-PbO 2), plattnerite being the other, beta form. The mineral was first reported in 1988 and its name reflects the scrutiny and efforts required to identify it from a very limited amount of available sample material.
Plattnerite is found in numerous arid locations in North America (US and Mexico), most of Europe, Asia (Iran and Russia), Africa and Southern and Western Australia.It occurs in weathered hydrothermal base-metal deposits as hay-like bundles of dark prismatic crystals with a length of a few millimeters; the bundles grow on, or sometimes within various minerals, [5] including cerussite ...
Name Meaning SI unit of measure alpha: alpha particle: angular acceleration: radian per second squared (rad/s 2) fine-structure constant: unitless beta: velocity in terms of the speed of light c: unitless beta particle: gamma: Lorentz factor: unitless photon: gamma ray: shear strain: radian
These commentators found that Aristotelian physics had difficulty explaining projectile motion. [note 15] Aristotle divided motion into two types: "natural" and "violent". The "natural" motion of terrestrial solid matter was to fall downwards, whereas a "violent" motion could push a body sideways.
The following is a list of notable unsolved problems grouped into broad areas of physics. [1]Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result.
In classical mechanics, the central-force problem is to determine the motion of a particle in a single central potential field.A central force is a force (possibly negative) that points from the particle directly towards a fixed point in space, the center, and whose magnitude only depends on the distance of the object to the center.
The name lead hydrate has sometimes been used in the past but it is unclear whether this refers to Pb(OH) 2 or PbO·xH 2 O. [ 7 ] [ 8 ] In 1964 it was believed that such a simple compound did not exist, as lead basic carbonate ( 2PbCO 3 ·Pb(OH) 2 ) or lead(II) oxide (PbO) was encountered where lead hydroxide was expected. [ 9 ]