Zirconia, an oxide of zirconium, is often used as an affordable diamond substitute. Just like diamond, it is a colorless crystal which sparkles under sunlight. Which of the following physical properties do you think would help in differentiating between diamond and Zirconia—melting point, density, or physical state?

A solid white substance A is heated strongly in the absence of air. It decomposes to form a new white substance B and a gas C. The gas has exactly the same properties as the product obtained when carbon is burned in an excess of oxygen. Based on these observations, can we determine whether solids A and B and gas C are elements or compounds?

The radius of an atom of tungsten (W) is about 2.10 Å. (b) How many tungsten atoms would have to be lined up to create a wire of 2.0 mm?

In the process of attempting to characterize a substance, a chemist makes the following observations: The substance is a silvery white, lustrous metal. It melts at 649 °C and boils at 1105 °C. Its density at 20 °C is 1.738 g/cm³. The substance burns in air, producing an intense white light. It reacts with chlorine to give a brittle white solid. The substance can be pounded into thin sheets or drawn into wires. It is a good conductor of electricity. Which of these characteristics are physical properties, and which are chemical properties?

Give the chemical symbol or name for each of the following elements, as appropriate: (a) rhenium (b) tungsten (c) cesium (d) hydrogen (e) indium

The radius of an atom of tungsten (W) is about 2.10 A . (a) Express this distance in nanometers (nm). Express this distance in picometers (pm).

Give the chemical symbol or name for each of the following elements, as appropriate: (f) As (g) Xe (h) Kr (i) Te (j) Ge.