PSSA Prep #2

Which example provides the best description of a system that is gaining more potential energy than kinetic energy?

• A hammer strikes a nail

• A soccerball rolls across a field.

• A marshmallow rests on a toy catapult.

• A rubber band stretches between two fingers.

A scientist examined a colorless gas, which had a density between 1 .30 and 1 .60 g/L and a boiling point between −190 and −180°C . The gas reacted with sodium (Na) metal . Based on the data in the table, what is the most likely identity of the gas?

• argon ( Ar )

• fluorine ( F2 )

• hydrochloric acid ( HCl )

• oxygen ( O2 )

A fossil collector found crinoid fossils. The collector did some research and read the information shown. What can the collector best infer about the area where the fossil was found?

• The area may once have been the site of an ocean.

• The rocks in the area most likely formed in the last 1,000 years.

• The area was most likely also a habitat for sea stars and sea urchins.

• The rocks in the area may have been moved from a different location.

CH4 + 2O2---> CO2 + 2H2O

Which statement correctly describes the reactants in the reaction shown?

• CH4 and O2 are the reactants because they combine to form new compounds.

• CH4 and O2 are the reactants because they have the highest number of atoms.

• CO2 and H2O are the reactants because they are formed following an initial reaction.

• CO2 and H2O are the reactants because they both exist as gases at room temperature.

The germ theory of disease states that diseases are caused by microorganisms. These organisms are too small to be seen by a human eye unless they are magnified by a microscope. The spread of disease results from these organisms entering a host. Which statement best explains how this theory is different from an opinion?

• The germ theory of disease was made by scientists, but opinions are made by nonscientists.

• The germ theory of disease does not change, but opinions can change when new discoveries are made.

• The germ theory of disease is a group of ideas that scientists believe are true, but only nonscientists believe opinions are true.

• The germ theory of disease is supported by evidence collected by many scientists over time, but opinions can be made without evidence.

The drawing shows a cycle that repeats regularly. Which factor primarily determines the length of this cycle?

• the tilt of Earth on its axis

• the Moon’s rate of rotation on its axis

• the distance between Earth and the Sun

• the Moon’s rate of revolution around Earth

The three parts of the wheat plant’s kernel are used for food. Which list correctly orders the steps for getting wheat-based food products to people so that people can use the products in their homes?

• grinding at the mill, packaging products, harvesting from the field, transporting to grocery stores

• harvesting from the field, grinding at the mill, packaging products, transporting to grocery stores

• grinding at the mill, harvesting from the field, transporting to grocery stores, packaging products

• harvesting from the field, grinding at the mill, transporting to grocery stores, packaging products

Which statement is an inference that is best supported by the data shown in the chart?

• The students’ heart rates increase with exercise.

• Student X’s heart rate is higher after exercise than at rest.

• Student Y’s heart rate is higher at rest than student Z’s at rest.

• The students’ heart rates during exercise are greater than after exercise.

Energy from the wind is used to rotate the blades of the wind turbine. Which sequence shows the conversion of energy that occurs at a wind turbine?

• solar energy -->  mechanical energy--> electrical energy

• kinetic energy--> mechanical energy-->  electrical energy

• chemical energy --> potential energy --> mechanical energy

• potential energy -->  gravitational energy -->chemical energy

Which process of heat transfer is shown in the diagram?

• Convection

• Conduction

• Insulation

• Radiation