Which of the following correctly shows the flow of energy in a food chain? a hawk ⇒ snake ⇒ mouse ⇒ grass
b grass ⇒ hawk ⇒ snake ⇒ mouse
c mouse ⇒ snake ⇒ hawk ⇒ grass
d grass ⇒ mouse ⇒ snake ⇒ hawk

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

Answer///(d) atoms contain small,negatively charged particles;