Question

analyzing the elements of a scientific method
read the following story and then answer the questions.
a scientist wants to find out why sea water freezes at a
lower temperature than fresh water. the scientist goes to the
library and reads a number of articles about the physical
properties of solutions. the scientist also reads about the
composition of sea water. the scientist travels to a nearby
beach and observes the conditions there. the scientist notes the
taste of sea water and other factors such as waves, wind, air
pressure, temperature, and humidity. after 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.\ the 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 -1°c
d. leaves the beakers in a freezer for 24 hours.
after 24 hours, the scientist examines both beakers and fins the fresh water to be frozen. the
salt water is still a liquid. the scientist writes in a notebook, \it appears that salt water freezes at a
lower temperature than fresh water.\ the 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.\
questions:

1. which statement(s) contain conclusions?__________________________

__________________________

1. which statement(s) contains a hypothesis?__________________________

__________________________

1. which statement(s) contain observations?__________________________

__________________________

1. which statement(s) describe an experiment?__________________________

__________________________

1. in which statement is the problem described?__________________________

__________________________

Explanation:

1. A conclusion is a statement that summarizes the results of an investigation. "It appears that salt water freezes at a lower temperature than fresh water." and "I suggest that the reason sea water freezes at a lower temperature is that sea water contains dissolved salts, while fresh water does not." are conclusions as they summarize the findings of the experiment.
2. A hypothesis is an educated guess. "If sea water has salt in it, it will freeze at a lower temperature than fresh water." is a hypothesis as it is a prediction made before the experiment.
3. Observations are statements based on what is seen, heard, etc. "The scientist notes the taste of sea water and other factors such as waves, wind, air pressure, temperature, and humidity." is an observation as it describes what the scientist noticed.
4. An experiment is a procedure carried out to test a hypothesis. "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 - 1°C; d. Leaves the beakers in a freezer for 24 hours." describes the steps of the experiment.
5. The problem is the question or issue to be investigated. "A scientist wants to find out why sea water freezes at a lower temperature than fresh water." describes the problem.

Answer:

1. "It appears that salt water freezes at a lower temperature than fresh water." and "I suggest that the reason sea water freezes at a lower temperature is that sea water contains dissolved salts, while fresh water does not."
2. "If sea water has salt in it, it will freeze at a lower temperature than fresh water."
3. "The scientist notes the taste of sea water and other factors such as waves, wind, air pressure, temperature, and humidity."
4. "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 - 1°C; d. Leaves the beakers in a freezer for 24 hours."
5. "A scientist wants to find out why sea water freezes at a lower temperature than fresh water."