Question

1. sandy observes the phases of the moon during a two-week period. she sketches and labels the phases and shares her drawings with the class. which statement best describes sandy’s investigation?

(f) it involves modeling.
(g) it involves experimentation.
(h) it involves repeated observations.
(i) it involves both experimentation and repeated observations.

1. scientists include controls in their experiments. why is a control important?

(a) it helps scientists share results.
(b) it helps scientists form their first hypothesis.
(c) it helps scientists record their repeated observations.
(d) it helps scientists compare their results to a standard.

1. a teacher writes the following note on a student’s experimental design: “you did not identify and control variables.” why is it important to identify and control variables?

(f) because a scientist must observe data
(g) because a scientist must form a hypothesis
(h) because a scientist must know which variable causes change
(i) because a scientist must know which variable to use for making a model

1. michael rides a bike made by company a. luis rides a bike made by company b. how can michael and luis determine in a scientific way whose bike has tires that last longer?

(a) read information about the tires from each manufacturer.
(b) ask ten classmates who ride each bike which tires last longer.
(c) have each student ride their own bike for 25 days, then compare the tires.
(d) use a machine to test the bikes in the same way for 25 days, then compare the tires.

1. a doctor says that drinking two glasses of milk in the morning will give students more energy. which of the following would be good scientific evidence for or against the doctor’s claim?

(f) a brochure from the doctor stating the benefits of milk
(g) data from scientific investigations about drinking milk in the morning
(h) a tv advertisement that drinking milk in the morning gives people plenty of energy
(i) statements from five people about how drinking milk in the morning gives them energy

1. when andrew conducts an investigation, he repeats the investigation several times. why does andrew do this?

(a) to create inventions
(b) to get consistent results
(c) to do the work very safely
(d) to be sure the work is correct

Explanation:

Question 12

Sandy observes moon phases over two weeks, sketches, labels, and shares. Modeling involves representing a phenomenon (sketches of moon phases), experimentation would involve manipulating variables (not done here), repeated observations would be multiple observation sessions (she does it over two weeks but the key is the sketching as a model). So the correct option is about modeling.

Controls in experiments are used to have a standard to compare results against. Option A is about sharing results, B about forming hypothesis, C about recording observations—none relate to control's purpose. Control helps compare to a standard.

Identifying and controlling variables is important to know which variable causes a change (to determine cause - effect). Option F is about observing data, G about forming hypothesis, I about making a model—none match. Knowing the causal variable is key.

Answer:

F. It involves modeling.

Question 13