Mastery Assignment- Nature of Science

It is January and Haley, Sarah and Becky are tired of having cold feet while waiting for the school bus to come in the morning. They decide to design an experiment to test the effectiveness of wool, cotton and nylon as insulators. They fill identical bottles with 200 ml of water at 100 C and place inside each sock. They take the temperature of the water after 20 minutes. What is the control variable?

• The identical bottles with 200 mL
• The type of insulator
• The different girls
• The temperature of the water after 20 minutes

A study was done with white rats to see if the number of offspring born with birth defects was related to the number of minutes of exposure to x-rays by the mother rats. What is the independent variable?

• Number of offspring born with defects
• The white offspring
• Number of minutes exposed to x-rays
• The mother rats

In 1897, Joseph Thomson discovered that atoms contain electrons.  He proposed a change in the atomic theory of that time, and the theory was modified because of his discovery.  Since Thomson’s discovery, atomic theory has been further modified.  What is the best explanation for why scientific theories are modified?

• Theories more than ten years old are usually out of date.
• Scientists want to prove that the work of other scientists is wrong.
• New evidence that supports a revision prompts scientists to modify earlier theories
• So much information is available today that it is harder to focus research and disprove theories

Which of the followings describe an experiment?

• Observation of plants or animals in their natural environment
• Physical or mathematical representation of an object or process
• An organized procedure to study something under controlled conditions
• Random collection of data for comparative purposes

Which of the following is a scientific law?

• If an object belongs to someone else, you cannot take ownership of it.
• Energy can be transformed from one form to another but the total amount of energy will never change.
• An individual under the age of 18 cannot work longer than 8 hours a day.
• An individual must not harm another individual.

The dependent variable can be define as the variable that _______

• Is affected by the change the scientist make. 
• Is changed by the scientist to tests it's effect on something.
• Is purposely unchanged by the scientist to make sure the experiment is valid. 
• Controlled by the scientist.

A study was done with white rats to see if the number of offspring born with birth defects was related to the number of minutes of exposure to x-rays by the mother rats. What is the control variable?

• Number of offspring born with defects
• White rats
• Number of minutes exposed to x-rays
• The mother rats

The amount of algae growth in lakes seems to be directly related to the number of sacks of fertilizer sold. Identify the independent variable in this experiment.

• Algae growth
• The lakes
• Fertilizer 
• Number of fertilizer sold

The independent variable is the variable that ________. 

• Is affected by the change the scientist make. 
• Is changed by the scientist to tests it's effect on something.
• Is purposely unchanged by the scientist to make sure the experiment is valid. 
• Is measured by the scientist. 

The control variable (s) can be define as the variable (s) that _______

• Is / are affected by the change the scientist make. 
• Is /are changed by the scientist to tests it's effect on something.
• Is/are purposely unchanged by the scientist to make sure the experiment is valid. 
• Is /are tested by the scientist.