Quick Lab Write-up Student Examples

                              Science Lab- River’s Load                        

            Our Lab today was on a river’s load.  Our question for the Lab was “What sediment will settle first, second, and third?”  My hypothesis was that the rock would settle first, the sand would settle second, and that the salt would basically settle last. 

            To test my hypothesis, I used a number of material and supplies.  I used, for the actual material in the bottle, 300ml of water, 194g of rock, 135g of sand, and 34g of salt.  I also used a water bottle to put the sediments in, a funnel so that the material would not spill all over the place when we poured it into the bottles, a pair of scales to measure out the ingredients, a graduated cylinder to measure out the water from the sink, pans to put our funnels over as extra security, and little plastic bowls to hold the material as it was on the scales or waiting to be measured out. 

            First, we had Jim get the material and the supplies.  We then immediately began measuring out appropriate amounts of sediment into our bottles.  Our group did not really care if the bar on the scale was a little high or low; it just had to be almost.  After we put in the water and shook it up, it seemed like just pond scum.  But after a while, it began to settle and we began to analyze what had happened.

            The rock had settled first, to none of our surprise.  Then the sand settled but filtered in around the rocks, giving the false appearance of the sand settling first.  Last of all, the salt… didn’t settle at all.  It just remained dissolved in the murky water. 

            In conclusion, my hypothesis was (arguably) correct.  The rock had settled first and the sand second, even though the sand filtered down to the bottom later.  Last of all, the salt never really settled, but dissolved into the murky water.  In this project we identified clearly three forms of river’s load.  There was the bed load, which were the rocks and large pieces of gravel bouncing around all over before being “deposited” on the bottom.  Then there was the suspended load, which were the sand and small chipped pieces of rock held in suspension and floating in the middle of the water for a while before eventually also being “deposited” upon and between the rocks.  And there is also the dissolved load, including the salt and other minerals dissolved from the sand and rock.

Science Write-up
River's Load

          The lab we did was River’s Load. The question we needed to answer was “what sediment will settle first, second, and third?” For the loads, we used rocks, sand, and salt for our test.

          For my hypothesis, which is an educated guess based on what I know, I guessed that the sand will settle first, salt next, then rocks. I guessed sand will be firsts because sand can mix in with the dirt around the dirt. Salt can do the same thing, but rocks will just crash around before depositing.

          To test my hypothesis, we had to go through several steps. In our group, we first grabbed what we needed. Everybody had a bottle and water would be available at the sink, so we snagged some rocks, sand, and salt from the counter. We adjusted the scale so that it would balance out 194 grams because that was the requirement for the rocks. We grabbed the rocks out of the huge container we had with a cup and placed them on the scale until it balanced with 194 grams. Then we placed them in our bottles once there was exactly 194 grams of rocks. When everybody had their rocks inside their bottles, we changed the scale to match 135 grams, what we needed for sand. The sand was a bit harder to place on the scale without making a mess, but using the cup, we got it on there and matched the weight with the one on the scale. One by one, we got the grains of sediment in our bottles by using the funnel. When everybody received their sand, we adjusted the scale once more for salt’s requirement, 34 grams. Because we didn’t need much salt, we used a small, plastic spoon to place the salt on the scale. We used the funnel to pour the salt into our bottles, which were now quite heavy. The group members who received their salt first went ahead with the water part, and the others would do it later. To measure out 300 milliliters, we had to fill the graduated cylinder three times, and pour it into our water bottles with great care. Once we had all of our items in, we shook the bottle and then watched it settle.

          As the bottle settled for an entire day, we could analyze the results. According to my bottle, the sand settled first, the rocks next, and the salt never settled because it dissolved first. It was settling quite slowly throughout the day, and it was tempting to shake it up. However, Mr. Armacost told us that it would take even longer if we shook it up, so I didn’t and merely observed the sand and rocks fall to the bottom of the water bottle.

          After I saw the results, my conclusion came up to me. I realized that my hypothesis about the sand was correct. It was the one that settled first. But I forgot that the salt would dissolve, so I was incorrect about the salt. The rocks were the one to settle after the sand.