Question

give reasons for the following:a) aluminium is used in making aircrafts
b) graphite is used in the leads of pencils

Answer 1

because Aluminium is very light graphite is soft and can be easily placed in the pencil wood

Answer 2

b)graphite is the actually "lead" material that's used in pencils. This is the ideal material because graphite chemically forms a carbon bond. Graphite is easy to work with because it is soft and can be encased into a wooden barrel.
a)'s strong, lightweight, and naturally resistant to corrosion. Some companies alloy titanium with iron or manganese to construct the frame and engines for airplanes. ... Aluminum isn't the strongest metal, but it maintains a perfect balance of strength and low weight that make it ideal for airplanes.