Answer:
giant covalent structures
Explanation:
Covalent solids are made up of atoms joined to one another by covalent bonds to form a giant lattice. The covalent bonds are very strong, this makes the giant covalent solids to be hard and possess high melting points. Covalent solids are nonconductors of electricity due to the absence of free electrons in the structure.
Diamond, graphite and boron nitride are all examples of giant covalent structures.
Examples of physical properties are: color, smell, freezing point, boiling point, melting point, infra-red spectrum, attraction (paramagnetic) or repulsion (diamagnetic) to magnets, opacity, viscosity and density.
The answer is All of them
Atmospheric pressure is measured with a barometer. A barometer consists of an evacuated vertical tube with its top end closed and its bottom end resting in a container of mercury that is open to the atmosphere The pressure exerted by the atmosphere acts on the exposed surface of the liquid to force mercury up into the tube. Sea level atmospheric pressure will support a mercury column generally not more than 29.92-in. high. Thus, the standard for atmospheric pressure at sea level is 29.92 in.-Hg, which translates to an absolute pressure of 14.69 psia.
The two basic reference points in all these measurements are standard atmospheric pressure and a perfect vacuum.