If a substance can be separated by physical means and it is not the same throughout, what is it? question 18 options: a heterogeneous mixture a homogeneous solution a pure substance a compound an element

Abody of weight 60 kg is standing in a lift the lift going upward with a uniform velocity of 4.9 metre per second slows down and stops in two seconds then apparent weight of the body during the slow down process is

When a neutral charge, comes into contact with a positive charge they repel each other nothing happens the neutral charge becomes negative they attract each other

What happens to the light rays when they hit the specimen?