Match the terms question 6 options: force static friction rolling friction sliding friction 1. for force when two solid surfaces slide over each other 2. the force when an object rolls across a surface 3. the force that exists between a stationary object and the surface on which it's resting. 4. any push or pull on an object

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.