Stanford Achievement Science Concepts Questions and Answers

Question 1

A student places a metal spoon in a cup of hot soup. After a few minutes, the handle of the spoon becomes warm. Which of the following best explains this phenomenon?

Accepted Answer

Heat from the soup is transferred through the spoon by conduction.

Answer

Conduction is the transfer of heat through direct contact. The hot soup transfers thermal energy to the spoon's molecules, which then vibrate and transfer that energy along the length of the spoon to the handle.

Question 2

A scientist is testing the effect of different amounts of fertilizer on the height of tomato plants. Each plant is given the same amount of water and sunlight. What is the independent variable in this experiment?

Accepted Answer

The amount of fertilizer used.

Answer

The independent variable is the factor that the scientist intentionally changes or manipulates to observe its effect. In this case, the scientist is changing the amount of fertilizer to see how it affects plant height.

Question 3

In a forest ecosystem, which of the following is an example of a producer?

Accepted Answer

An oak tree making its own food using sunlight.

Answer

Producers are organisms that create their own food, usually through photosynthesis. An oak tree uses sunlight, water, and carbon dioxide to produce its own energy, making it a producer at the base of the food web.

Question 4

Which of the following is a primary requirement for the process of photosynthesis to occur?

Accepted Answer

Carbon Dioxide

Answer

Photosynthesis is the process where plants use sunlight, water, and carbon dioxide to create their own food (glucose) and release oxygen as a byproduct. Therefore, carbon dioxide is a necessary reactant, or input, for the process to begin.

Question 5

After a rainstorm, a puddle of water on the sidewalk disappears over a few hours on a sunny day. This process is known as:

Accepted Answer

Evaporation

Answer

Evaporation is the stage of the water cycle where liquid water turns into water vapor (a gas) and rises into the atmosphere. The sun's heat provides the energy for this process to occur, causing the puddle to 'disappear'.

Stanford Achievement Test Practice Test

Stanford Achievement Test Practice Test

Stanford Achievement Science Concepts Questions and Answers