Read the following story and then answer the questions.
1a scientist wants to find out why sea water freezes at a lower temperature than fresh water. 2the scientist goes to the library and reads a number of articles about the physical properties of solutions. 3the scientist also reads about the composition of sea water. 4the scientist travels to a nearby beach and observes the conditions there. 5the scientist notes the taste of sea water and other factors such as waves, wind, air pressure, temperature, and humidity. 6after considering all this information, the scientist sits at a desk and writes, "if sea water has salt in it, it will freeze at a lower temperature than fresh water." 7the scientist goes the laboratory and does the following:
a. fills each of two beakers with 1 liter of fresh water
b. dissolves 35 grams of table salt in one of the beakers
c. places both beakers in a freezer at a temperature of l°c
d. leaves the beakers in a freezer for 24 hours.
8after 24 hours, the scientist examines both beakers and finds the fresh water to be frozen. 9the salt water is still a liquid. 10the scientist writes in a notebook, "it appears that salt water freezes at a lower temperature than fresh water." 11the scientist continues, "i suggest that the reason sea water freezes at a lower temperature is that sea water contains dissolved salts, while fresh water does not."
in which statement is the problem described?
question 7 options:
sentence 1
sentences 9
sentences 7
sentence 6

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

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.

Na chemical reaction, activation energy increases the of the reactants. this outcome causes the particles to collide, which results in the of new products.