1.At sea level, an odourless and colorless materials boils at 100⁰C and freezes at 0⁰C.what inference can be drawn from this observation?
a.the material is a metal
b.the material is a non metal
c.the material is a mixture
d.the material is a pure substance
2.table salt is made up of two elements,sodium and chlorine.sodium is a very reactive metal.once you have placed even a pea-size of this metal in water,a voilent reaction occurs.on the other hand exists as a gas.it is used as a poisonous chemical weapon during the war.but when a chemical change between the two takes place,it would form a new and non-poisonous substance known as sodium chloride.which of the following DOES NOT correctly describe this observation.
a. sodium and chlorine are both substances while sodium chloride is a mixture.
b.sodium, chlorine and sodium chloride have fixed melting and boiling point.
c.sodium chloride can be further broken down into simpler substance.
d.all the three materials are substances​