Question

scientific variables read the paragraph below, then identify the variables in each experiment. being able to identify the scientific variables in an experiment is an important skill for any scientist. when designing an experiment, it is important that you only test one variable at a time. the variable that you are testing is known as the independent variable, or iv. the part of the experiment that responds to the iv is known as the dependent variable, or dv. the dependent variable is usually the part of the experiment that you measure to see if your hypothesis worked or not. independent variable - part of the experiment that is tested or changed by the scientist (starts with the letter i; i change) dependent variable - part of the experiment that responds to changes in the independent variable; is measured for results 1. you decide to test whether charcoal helps purify water or not. you design a filter that contains charcoal and run water from a nearby stream through the filter. afterward, you test the water for contaminants. independent variable: _iv_ dependent variable: _dv_ 2. you decide to test whether an insect repellant is effective or not. you apply insect repellant to your right arm and count how many insects land on your arm over an hour. independent variable: _ dependent variable: _

Explanation:

Step1: Identify IV for water - purification experiment

The scientist is testing the presence of charcoal in the filter. So, the independent variable is the presence of charcoal in the water - filter.

Step2: Identify DV for water - purification experiment

The scientist measures the amount of contaminants in the water after filtering. So, the dependent variable is the amount of contaminants in the water.

Step3: Identify IV for insect - repellent experiment

The scientist is testing the application of insect - repellent. So, the independent variable is the application of insect - repellent on the arm.

Step4: Identify DV for insect - repellent experiment

The scientist counts the number of insects that land on the arm. So, the dependent variable is the number of insects that land on the arm.

Answer:

1. Independent variable: Presence of charcoal in the water - filter

Dependent variable: Amount of contaminants in the water

1. Independent variable: Application of insect - repellent on the arm

Dependent variable: Number of insects that land on the arm