praxis elementary science 5005 practice test

A series of tests developed by ETS to assess the skills and knowledge of prospective teachers.

Which THREE of the following are health problems associated with long-term exposure to air pollution?
  • A. Accelerated aging of the lungs
  • B. Increased lung capacity
  • C. Increased risk of asthma
  • D. Increased risk of cardiovascular disease
Correct Answer & Rationale
Correct Answer: A,C,D

Long-term exposure to air pollution can lead to several significant health issues. Option A, accelerated aging of the lungs, is accurate as pollutants can damage lung tissue over time, reducing function. Option C is also correct; exposure to air pollution is linked to a higher incidence of asthma, particularly in children, due to airway inflammation and increased sensitivity. Option D is valid as well; numerous studies show that air pollution significantly raises the risk of cardiovascular diseases due to systemic inflammation and oxidative stress. Conversely, Option B, increased lung capacity, is incorrect. Air pollution typically impairs lung function rather than enhancing it, leading to reduced capacity over time.

Other Related Questions

Which of the following is a true statement about sodium chloride (NaCl)?
  • A. It is a gas at room temperature.
  • B. It is a compound formed from two elements.
  • C. It is a mixture formed from two different compounds.
  • D. It is an element that is unstable and reactive.
Correct Answer & Rationale
Correct Answer: B

Sodium chloride (NaCl) is indeed a compound formed from two elements: sodium (Na) and chlorine (Cl), which combine in a fixed ratio through ionic bonding. Option A is incorrect; NaCl is a solid at room temperature, not a gas. Option C misrepresents NaCl as a mixture, but it is a pure compound, not formed from different compounds. Option D inaccurately describes NaCl as an element; it is a stable compound, not unstable or reactive under normal conditions. Thus, option B accurately reflects the nature of sodium chloride.
Which of the following is always true of a chemical change?
  • A. Color, shape, or texture is altered.
  • B. Mass is increased.
  • C. A new substance is formed.
  • D. Gas or vapor is generated.
Correct Answer & Rationale
Correct Answer: C

A chemical change always results in the formation of a new substance, which is a fundamental characteristic distinguishing it from physical changes. Option A is incorrect because while color, shape, or texture may change, these alterations do not confirm a chemical change unless a new substance is produced. Option B is misleading; mass is conserved in chemical reactions, so it does not necessarily increase. Option D, while often true (as gases can be produced), is not universally applicable; some reactions do not produce gas. Hence, the formation of a new substance is the definitive indicator of a chemical change.
A metal spoon that heats up while sitting in a bowl of hot soup is an example of heat transfer by:
  • A. conduction
  • B. convection
  • C. radiation
  • D. diffusion
Correct Answer & Rationale
Correct Answer: A

Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Which of the following best describes what happens when two magnets repel each other?
  • A. The objects are pulled toward one another.
  • B. The objects are pushed away from one another.
  • C. An electric spark jumps from one object to another.
  • D. Nothing happens until the objects are touched.
Correct Answer & Rationale
Correct Answer: B

When two magnets repel each other, they exert forces that push away from one another due to their like poles (north-north or south-south). This repulsion is a fundamental property of magnetism. Option A is incorrect because it describes attraction, which occurs when opposite poles (north-south) interact. Option C is misleading; electric sparks are not a typical result of magnet repulsion. Option D is also wrong, as repulsion occurs before any physical contact, demonstrating the active interaction between the magnets. Thus, the best description of this phenomenon is that the objects are pushed away from one another.