Question

Which among the following are commonly used for making safety pins?
A. Wood and glass
B. Plastic and glass
C. Leather and plastic
D. Steel and plastic

Answer 1

Hint :The combination of more than one metal or mixture of metal and a nonmetal in a fixed proportion are known as alloys. Certain elements are added to the mixture in a specific ratio which alter the properties of metals and strengthen the metals.

Complete Step By Step Answer:
One of the widely used alloys in day-to-day life is steel. The base metal of steel is iron to which carbon is added in a specific ratio to improve its strength and fracture resistance. The amount of carbon in steel varies up to $2.14\% $ of its weight.
The pure iron is ductile, soft and gets corroded when exposed to moist air but on adding carbon to it enhances the property of iron and the alloy i.e., steel formed is hard, brittle and prevents corrosions. Hence, steel has many applications in domestic as well as industrial sectors.
Some of the applications of steel are discussed below:
-Used in making tools like knives, razors, blades etc.
-Used in making the vessels.
-Used in railway tracks, wheels and gears.
Steel can also combine with polymers like plastic to give useful products. One of the common examples is safety pins. Steel and plastic are commonly used in making safety pins. Hence, option (D) is the correct answer.

Note :
It is important to note that when steel is mixed with $10.5\% $ chromium, about $1.2\% $ carbon and other components like nickel and nitrogen. Then the alloy formed is known as stainless steel and it is widely used in making cutlery and necessary machinery tools.