Question

1. what do scientists use models for?
2. name two methods scientists use to test predictions.
3. what is the difference between an independent variable and a dependent variable?

Explanation:

1. Scientists use models to represent complex systems, make predictions, and understand phenomena that are difficult to study directly.
2. Two common methods are experiments, where variables are controlled to observe effects, and observations, where natural - occurring events are watched and data is collected.
3. An independent variable is the variable that is changed or manipulated in an experiment. A dependent variable is the variable that is measured and is expected to change in response to the independent variable.

Answer:

1. To represent complex systems, make predictions, and understand difficult - to - study phenomena.
2. Experiments, Observations
3. An independent variable is manipulated; a dependent variable is measured and changes in response to the independent variable.