The document discusses materials used in engineering, including metals and non-metals. It notes that ferrous metals contain iron, with cast iron and steel being the two most important ones. Cast iron contains more carbon than steel. Some elements, like chromium, are added to steel to improve its properties such as corrosion resistance. Bronze is also identified as an alloy.

1. Activity 8 Materials
READING AND COMPREHENSION
1Engineers have to know the best and most economical materials to use.
2 Engineers must also understand the properties of these materials and how
they can be worked. 3There are two kinds of materials used in engineering -
metals and non-metals. 4We can divide metals into ferrous and non-ferrous
metals. 5The former contain iron and the latter do not contain iron. 6Cast
iron and steel, which are both alloys, or mixtures of iron and carbon, are the
two most important ferrous metals. 7Steel contains a smaller proportion of
carbon than cast iron contains. 8 Certain elements can improve the properties ·
of steel and are therefore added to it. 9For example, chromium may be
included to resist corrosion and tungsten to increase hardness. 10 Aluminum,
copper, and the alloys, bronze and brass, are common non-ferrous metals.
Study the following statements carefully and write down whether they are
true or not true according to the information expressed above.
(a) Non-metals are used by engineers.
(b) Cast iron contains more carbon than steel.
(e) Chromium improves the properties of steei.
(d) Copper contains iron.
(e) Bronze is an alloy.