Question

Why magnet did not attract the pen, pencil,and other thing but why magnet attract nickel,iron,cobalt.why?give reason of your answer ? Please it is a very important question

Answer 1

The magnetic properties of a material are governed entirely by the configuration of the electrons in that material.  In metals there are two types of electrons: bound electrons and free electrons.  The free electrons are free to move between atoms, and are the cause of conductivity in metals.  The bound electrons are stuck to the individual atoms.

Each electron, in addition to having charge, also has a “magnetic moment” which is a fancy way of saying that it’s a tiny bar magnet.  Generally the bound electrons will be paired off in opposite spin pairs.  This is like putting a North-South magnet next to a South-North magnet.  They almost completely cancel each other out.  However, sometimes (in iron, nickel, and cobalt for example) you’ll have one or more un-paired electrons.  The magnetic fields of these electrons aren’t canceled out by another, oppositely-oriented, electron.  As such they lend an overall magnetic field to the atom they inhabit..... hope it helps you

Answer 2

Magnet only attract those substances in which their entity has the property to align according to magnetic field lines mostly metalic material has this property but plastic graphite etc can't be attracted towards magnet because magnetic field doesn't affect them...