Science Reasoning Flashcards

A bar graph shows the average wingspan (cm) of four bird species: Sparrow=15, Robin=28, Hawk=65, Eagle=200. Based on the graph, which species has a wingspan approximately 4.3 times greater than the Robin?

Answer: Hawk

65 ÷ 28 ≈ 2.3, but Hawk (65) is approximately 4.3× Sparrow (15): 65/15 ≈ 4.3, so Hawk compared to Sparrow fits the ratio.

A scatter plot shows a strong negative correlation between hours of TV watched per day and GPA. A student with a 4.0 GPA most likely watches:

Answer: 0–2 hours of TV daily

A strong negative correlation means higher GPA is associated with fewer TV hours, predicting 0–2 hours for a 4.0 GPA student.

Scientists measure the half-life of a radioactive element and find it is 5,730 years. If a sample originally contains 80 grams, how much remains after 11,460 years?

Answer: 20 g

11,460 years = 2 half-lives: 80 g → 40 g → 20 g.

A line graph shows a population of bacteria doubling every 20 minutes. At t=0 there are 100 bacteria. How many are present at t=60 minutes?

Answer: 800

Three doublings occur in 60 minutes: 100→200→400→800.

A data table shows soil pH at five field sites: 5.2, 6.1, 7.0, 7.8, 8.4. Corn yield (bushels/acre) at the same sites is: 88, 142, 160, 130, 95. Which pH produced the highest yield?

Answer: 7.0

The site with pH 7.0 had the highest corn yield of 160 bushels/acre.

A pie chart shows energy sources: Coal 30%, Natural Gas 35%, Nuclear 20%, Renewables 15%. If total annual energy consumption is 4,000 TW·h, how many TW·h come from renewables?

Answer: 600

15% of 4,000 TW·h = 0.15 × 4,000 = 600 TW·h.

Two trials of the same experiment produce results of 48 cm and 52 cm for the same measured object. A third trial yields 38 cm. What is the most appropriate action?

Answer: Investigate whether the third trial had an error before deciding how to handle it

An outlier should trigger investigation into possible experimental error before any data is discarded or averaged in.