a)Titanium is called strategic metal as it can be use in producing space craft , aircraft and missiles. It is the fourth most abundant metal on the earth. Since it is resistant to salt water and acid corrosin it is used in making durable corrosion resistant alloys.

b)lons are electrically charge particle formed when atoms lose or gain electrons. They have the same electronic structure as noble gases metal atoms from positive ions why non metal atoms from negative ions day strong electrolytic forces of attraction between oppositely charged ions are called ionic bonds. iconic compounds have high melting and boiling points how I inform ions are electrically charged particles from when atoms does our brain electron this loss of games Lives a complete highest energy level so the electronic structure of an iron is the same as that a noble gas such as Helium neon Argon metal atoms are non metal atoms go in opposite direction when the iconics metal atom the electron electron in their highest energy level and become positively charged ions. non metal atoms gain and electron are electrons from another item to become negatively charged ions.

c)Aluminum is more reactive than iron but it doesn't corrode It is because of aluminium oxide layer. Aluminium outer surface layer is oxidized whenever it came in contact with the air and so result in aluminium oxide layer which is resistive in nature and remain attached to it. So due to this it act as protective layer to inner aluminium to get oxidized with air while in iron as the surface layer of iron is oxidized, it form rust which is not remain attached to iron and fall off exposing the inner iron for further oxidation.