Page 64 - 新思维科学学生用书7 样章

2.7 Compounds and mixtures

Compounds and mixtures

When atoms of elements are bonded tightly to form a compound, the properties of the compound are
completely different from the properties of the elements that it is made from.

For example, iron is a metal. It is hard, grey, strong, conducts heat and electricity and is magnetic.

Sulfur is a non-metal. It is yellow, brittle, does not conduct heat or electricity and is not magnetic.

This miner is carrying baskets of sulfur from the crater of a This blacksmith is using iron to make a bracelet.
volcano in Indonesia.

When these two elements are heated, they combine
together to form the compound iron sulfide. Iron sulfide is

not magnetic and does not conduct heat or electricity.

sulfur atom iron atom

When iron and sulfur are heated together, iron atoms and sulfur
atoms bond together to form the compound iron sulfide.

63