Which statement best explains how periods on the periodic table are organized?
A: increasing atomic number from left to right

Some students were investigating the relationship between position, time, and speed. The students marked the initial position of a toy car. The students set the car into motion and marked the position of the car each second. Which of these are most appropriate for recording and analyzing the students' data?
A: a table and a line graph

The iron in iron-rich red soils may not be in a form that can be taken up by tree roots. As a result, leaves and needles may look yellow. Some trees release acids that convert iron in soil to a usable form. This change in soil chemistry is a type of which process?
A: weathering

Which action is an example of an exothermic process?
A:
making ice cubes