Elements are arranged in the periodic table based on various patterns. for example, elements found in the rows near the top
a. have lower atomic numbers than the elements in the rows near the bottom.
b. have the same atomic numbers as the elements in the rows near the bottom
c. all have the same atomic number.
d. have higher atomic numbers than the elements in the rows near the bottom

Which statement correctly identifies the scientific question and describes why the question is scientific? question 1 refers to the supernatural. question 2 reflects a moral or social value. question 3 refers to something that can be measured. question 4 reflects a question that can’t be observed.

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.

Which of the following statements best distinguishes a hypothesis from a theory? a. theories are hypotheses that have been proved. b. hypotheses are guesses; theories are correct answers c. hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. theories are proved to be true; hypotheses are often contradicted by experimental results.