Chemistry
A chemist draws two molecular models. One model is drawn for formaldehyde (CH2O) and one model is drawn for formic acid (CH2O2) The chemist forgets to write the name above each model.
Formic acid is represented by model (1) (2). This model has a different number of (carbon, oxygen, hydrogen) atoms than the other model.
Formic acid is represented by model (2). This model has a different number of oxygen atoms than the other model.
Acidic - Blue
Neutral - Purple
Basic - Pink
Based on the data, what color flowers will a hydrangea plant produce when it grows in neutral soil that is then treated with garden lime over time?
The flower color will be (blue, pink, purple) because the acidity of the soil becomes (more acidic, neutral, basic.)
The flower color will be pink because the acidity of the soil becomes more basic (less acidic).
Garden lime raises the pH of soil over time, making it more basic. Based on the data (basic → pink), the flowers will change to pink.
The student wants to find reliable information about the development of golden rice and the environmental impacts of growing golden rice.
Which two sources are most likely to provide the student with credible information on golden rice.
an editorial column in a newspaper endorsed by more than 100 people
a monthly magazine that publishes articles reviewed and verified by a group of scientists
a website containing peer-reviewed papers on research findings with cited sources of information
a website owned by a company that produces and sells genetically modified seeds to farmers for profit
a monthly magazine published by a nonprofit organization that promotes organic farming and a healthy diet
• a monthly magazine that publishes articles reviewed and verified by a group of scientists
• a website containing peer-reviewed papers on research findings with cited sources of information
These sources are the most reliable because they involve scientific review processes, evidence-based research, and verification by experts.
A student learning about heat transfer makes a claim.
Some metals change temperature more rapidly than other metals.
The student proposes to test the claim in the lab by using metal rods made of iron (Fe), copper (Cu), and aluminum (Al) In addition to the metal rods, which piece of equipment would be useful for investigating the claim?
A. prism, heat lamp, screen, meterstick
B. beaker, digital scale, stopwatch, clamps
C. litmus paper, beaker, pan balance, battery
D. hot water, pan to hold water, stopwatch. thermometer
D. hot water, pan to hold water, stopwatch, thermometer
To test how quickly different metals change temperature, the student needs to:
Scientists discovered Mesosaurus fossils on the eastern coast of South America. The fossils are identical to ones found in southern Africa. These fossils are not found anywhere else on Earth.
Complete the sentences.
Though the two continents were once joined, (seafloor spreading, ocean currents, gravitational pull from the moon) caused movement of the continents to their current positions. The evidence supporting the claim that the continents were once joined includes the (shape of the Antarctic plate, environmental conditions that favored fossil formation, presence of identical fossils)
Though the two continents were once joined, seafloor spreading caused movement of the continents to their current positions.
The evidence supporting the claim that the continents were once joined includes the presence of identical fossils.
Why:
In June 1991, Mount Pinatubo in the Philippines erupted. The eruption released large amounts of gases, such as sulfur dioxide, water vapor, and carbon dioxide, into the atmosphere. Sulfur dioxide reacted with water to form aerosol particles, and an aerosol cloud formed that covered a large portion of Earth.
Students want to determine what effect the eruption had on global climate. Which question should the students investigate to best determine the effect?
A. What was the temperature of the lava that flowed onto Earth's surface when Mount Pinatubo erupted?
B. Was the amount of rain that fell on Mount Pinatubo in the days after the eruption greater or less than average?
C. Do aerosol particles of this type cause the amount of solar energy that reaches Earth's surface to increase or decrease?
D. How did the temperature of the gases as they were ejected from Mount Pinatubo compare to the temperature of the gases ejected from other volcanoes?
C. Do aerosol particles of this type cause the amount of solar energy that reaches Earth's surface to increase or decrease?
Mount Pinatubo released sulfur dioxide that formed aerosol particles in the atmosphere. These particles reflected incoming sunlight back into space, which reduced the amount of solar energy reaching Earth’s surface and led to a temporary cooling of global temperatures.