1. What is the central scientific puzzle presented by comparing skin cancer rates in Australia and Brazil?
- A. Brazil has a surprisingly low skin cancer rate for a country with a large population.
- B. Australia has a much higher skin cancer rate than Brazil, despite both countries receiving comparable amounts of sunlight.
- C. The amount of sunlight is the only factor determining a country's skin cancer rate.
- D. Skin cancer is more dangerous in the Southern Hemisphere than in the Northern Hemisphere.
2. In the scientific investigation of skin cancer rates, why is Brazil a useful country to compare with Australia?
- A. Because Brazil and Australia are both located in the Southern Hemisphere.
- B. Because Brazil has a much larger population, making the statistical comparison more dramatic.
- C. Because its similar level of sun exposure helps to control for that variable, pointing to other potential causes.
- D. Because Brazil's low cancer rate proves that sunlight exposure is not a significant health risk.
3. Based on the comparison between Australia and Brazil, what is the most logical conclusion a scientist can draw?
- A. Sunlight exposure is not a factor in the development of skin cancer.
- B. Other factors besides the total amount of sunlight contribute to Australia's high skin cancer rate.
- C. Australians must spend significantly more time outdoors than Brazilians do.
- D. The methods for diagnosing skin cancer in Brazil are less advanced than in Australia.
4. The observation that Brazil has a low skin cancer rate despite high sun exposure challenges which simple assumption?
- A. A country's skin cancer rate is determined solely by the amount of sunlight it receives.
- B. Genetic factors can play a role in an individual's risk for developing skin cancer.
- C. Public health campaigns can effectively reduce rates of preventable diseases.
- D. Skin cancer is a serious global health issue that requires further study.
5. A scientist observes that two towns at the same latitude have very different rates of asthma. Town A's rate is high, while Town B's is low. Following the logic from the Australia skin cancer mystery, what is the best next step?
- A. Look for other differing factors, like local industries or allergens.
- B. Conclude the difference is purely due to genetics.
- C. Assume air quality is the only possible cause.
- D. Immediately copy the public health policies from Town B to Town A.
6. A brightly colored flag becomes faded after being outside for an entire summer. This happens primarily because energy from sunlight...
- A. physically wears away the surface of the fabric over time.
- B. causes a chemical change in the molecules of the flag's dye.
- C. attracts dust and pollen particles that cover the original color.
- D. makes the dye molecules warmer, causing them to evaporate into the atmosphere.
7. A student observes that a puddle of water in a sunny spot on the pavement disappears faster than a puddle in the shade. This observation demonstrates that light is a source of what?
- A. Matter
- B. Energy
- C. Friction
- D. Moisture
8. Which statement best explains why leaving a newspaper in direct sunlight for a month causes it to become yellow and brittle, while keeping it indoors does not?
- A. Indoor air has more moisture, which protects the paper.
- B. The sun's light contains more energy than typical indoor light.
- C. The paper absorbs heat from the sun but reflects light from a lamp.
- D. Darkness reverses the chemical process that causes yellowing.
9. A plastic playground slide that was once brightly colored is now pale and chalky after several years outdoors. This transformation is an example of...
- A. a physical change caused by the transfer of light energy.
- B. the plastic slowly dissolving from exposure to rain.
- C. friction from use wearing away the colored layer.
- D. the plastic material naturally aging without external factors.
10. Which fundamental property of light explains its ability to cause physical changes like fading colors and drying materials?
- A. Its ability to travel in straight lines
- B. Its capacity to reflect off of most surfaces
- C. The speed at which it travels through a vacuum
- D. The energy it carries and transfers to objects