3) The following table gives information about six substances substance melting point 839 A B -188 -42 с 776 1497 D -117 78 E 1607 2227 F -5 boiling point 1484 102 electrical conductivity as a solid electrical conductivity as a liquid good good poor poor poor good poor poor poor poor poor good (a) Which substance could be a metal? [1] (b) State all the substances that are liquid at room temperature. [1] (c) Which substance could have a macromolecular structure similar to that of silicon (IV) oxide? (d) Which substance could be sodium chloride? [1]
Answers
Answer:
(a)Which substance could be a metal?
Answer:- A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero.
(b)State all the substances that are liquid at room temperature.
Answer:- At this temperature and ordinary pressure, only two elements are liquids
•Bromine.
•Mercury.
(c) Which substance could have a macromolecular structure similar to that of silicon (IV) oxide?
Answer:- Si(IV) oxide is macromolecular with a non layer structure similar to diamond.
I hope this helps you... frnda...
(a) A metal may be a chemical element such as iron, an alloy such as stainless steel, or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero.
(b) At this temperature and ordinary pressure, only two elements are liquids.They are mercury (a metal) and bromine (a halogen). Four other elements are liquids slightly warmer than room temperature. They are francium, cesium, gallium, and rubidium (all metals)
(c) Si(IV) oxide is macromolecular with a non layer structure similar to diamond.Silica shows tetrahedral structures with silicon as a central atom and four oxygen atoms in tetrahedral manner surround the silicon atom.
1. In the same way it forms three dimensional network solid, covalently bonded with each other in tetrahedral geometry. The structure is very similar to the one we use to see in diamond. Oxidation state of silicon in silicon dioxide is four.
(d)salt (NaCl), sodium chloride, mineral substance of great importance to human and animal health, as well as to industry. The mineral form halite, or rock salt, is sometimes called common salt to distinguish it from a class of chemical compounds called salts.
1.We use aqueous silver nitrate (AgNO3(aq)) solution to identify chloride ion from this we identify the subtance could be sodium chloride or not