A Scientist noticed that cattails grew only in swampy parts of his backyard. He decided to try to find out why. He
went to the library and found out the following facts: Cattails are not found in deserts, Cattails are usually found
in many swamps, Cattails sometimes grow in rivers and streams. The scientist thought for awhile, then said, "|
think I have figured out the answer. Cattails need a lot of water to grow." He then went into his yard and dug up
100 cattails. He divided them into four groups. Each group contained 25 cattails. All of the groups were grown in
the same type of soil, they all received the same amount of light, and they were all kept at the same
temperature. There was only one difference between the groups. Group 1 received 4 mL of water a day. Group 2
received 3 mL of water a day. Group 3 received 2 mL of water a day. Group 4 received 1 mL of water each day.
Every day he went out and measured the plants. After 30 days he observed that the plants in group 1 had grown
an average of 8 cm. The plants in group 2 had grown an average of 4 cm. The plants in group 3 had grown an
average of 2 cm. The plants in group 4 had grown an average of only 1 cm. He then decided that the amount of
water that a cattail receives affects its growth. Plants that receive more water, grow more. The scientist then
repeated his experiment using another 100 cattails.

Select each correct answer. more than one answer may be correct. which of the following is a characteristic of unicellular organisms? they can possess tissues and organs. all of their functions are performed by a single cell. they are usually microscopic. each of their cells is specialized to perform a specific function.

Which fact represents evidence for the big bang theory?

Show transcript transcripts online experiment: atomic structure [the history of atomic theory] this animation will you test rutherford’s hypothesis that it took a great number of shots to actually hit the nucleus because the size of the atom was so much larger than the nucleus.[clipboard and pencil with a diagram of rutherford’s gold foil experiment] we are going to use a cardboard box to represent the atom, a wooden block to represent the nucleus, and marbles to represent the alpha particles. [animated cardboard box, wooden block, and marbles] the box’s measurements are: length = 50 cm, width = 25 cm, and height = 25 cm. the measurements of the block are: length = 10 cm, width = 10 cm, and height is 5 cm. jose and priscilla will conduct the experiment. [animated boy and girl] priscilla put the block in the box on the floor. jose will close his eyes and drop marbles into the box trying to hit the block. priscilla will count the number of times the marbles hit the block and move the block in the box after each hit. [animated block moving inside the box. marble dropping into the box.] here is priscilla’s data of how many times the marble hit the block. out of 100 marble drops or shots, the marble hit the block 32 times. [data table: first column: marble, with rows 1 to 100; column 2: hit, with rows indicating yes or no. last row: total hits] now you can follow the directions in the experiment to present your findings. present your findings when you are finished with the experiment, complete the following data analysis and record your answers in the essay box below. determine the volume of the box and the block. determine the ratio of the block to the box: multiply this number by 100 to turn it into a percent. complete this statement: the volume of the block is percent of the volume of the box. determine the ratio of the number of hits to the number of shots: multiply this number by 100 to turn it into a percent. complete this statement: the block was hit percent of the time. compare the results of step 2 to the results of step 3. are the percentages similar? write a conclusion discussing the following items: based on your findings, do you think rutherford's hypothesis was reasonable? restate rutherford's hypothesis and describe how you tested it. state whether your results support the hypothesis. if they do not, can you suggest some error in experimental procedure (other than general human error) that might explain it? finally, explain how this experiment confirms the nuclear model of the atom and the idea that most of the atom is empty space.