Cumulative Exam — Cumulative exam Answers

Carlos is making phosphorus trichloride using the equation below. 2P +3Cl2 _PCl3What coefficient of PCl3 would show that the law of the conservation of mass is represented in the chemical equation?

Which has most likely been peer reviewed?

An atom of carbon (C) forms covalent bonds with two atoms of oxygen (O) to form carbon dioxide. How are the valence electrons of these atoms rearranged to form the bonds?

Alai is comparing the physical property of two materials. He is hitting each with a hammer to observe what happens. What physical property of the materials is Alai most likely observing?

Lava is rock that has undergone a physical change and has liquefied. What is known about this change?

Which is most likely an example of pseudoscience?

Which statement best describes one positive and one negative way that society was impacted by the use of DDT?

This is how platinum appears in the periodic table.

Read the passage.In Federal Drug Administration clinical trials, people who added a particular drug to diet and exercise were able to lose weight, as well as lower their blood pressure. This drug was evaluated in two clinical studies involving overweight adults with high blood pressure. The results of the trials showed that 48 percent of people taking this drug lost some of their body weight. The other group in this trial consisted of people who were not taking this medicine, and only 23 percent of them lost some weight.

In an investigation, the atoms of a certain substance lose energy during a change of state. Before the change, the atoms are far apart and move constantly at high speeds and in all directions. After the change, the atoms are close together but are able to slide past one another.Use the diagram that shows changes of state between solid, liquid, and gas to answer the question.

Which statement correctly describes the electrons in a water molecule?

A cylinder at left with balls evenly spaced throughout the cylinder has an arrow leading to a cylinder at right cylinder with balls in a layer at its bottom.

Which atoms and/or ions expand in all directions?

Chang makes the diagram below to compare Gay-Lussac’s law and Charles’s law.

Zora takes notes in class as shown below.Positive Convenience Increased multitasking Increased efficiency Negative Expense May cause cancer May lead to decreased exercise

Jeanine wants to perform an experiment on a group of teenagers involving an experimental new drug. She is not granted permission to conduct her study.What is most likely the problem that Jeanine is having with performing her experiment?

Chris drew a diagram to compare the ways in which different organisms obtain nitrogen.

The diagram illustrates the water cycle.

At the center, 6 unmarked red balls are interspersed with 4 blue balls marked with plus signs. A green cloud with 2 concentric white lines surrounds the center, with 2 small green balls marked with minus signs on the inner white line and 2 small green balls marked with minus signs on the outer white line.

Which statement correctly describes compounds?