A student placed some clean rocks in a clear plastic jar. The jar was filled with clean water and covered with a lid. The student then shook the jar up for five minutes. The student noted that smaller pieces had broken off some of the rocks and that there was a fine grit on the bottom of the jar. Which change of Earth's surface was the student modeling? * A. mechanical weathering B. chemical weathering C. erosion of sediments D. forming deltas

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.

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

explanation: