A
What theory states that Earth’s continents were once joined and slowly moved to their present locations?
Answer: Continental Drift Theory
Points: 50
Scientists discover an offshore trench, earthquakes that become deeper farther inland, and volcanoes on a nearby continent. What process explains these observations?
Answer: An oceanic plate is subducting or sinking beneath a continental plate.
Points: 175
Two clear solutions are mixed, and a solid suddenly forms. What is the solid called?
Answer: A precipitate
Points: 75
What process occurs when molten material rises at a mid-ocean ridge, cools, and forms new oceanic crust?
Seafloor spreading
Points: 75
A homemade insect-repellent spray remained effective for 18, 20, and 19 minutes. A commercial spray remained effective for 25, 24, and 26 minutes. What conclusion is supported by the results?
Answer: The commercial spray remained effective longer than the homemade spray under the tested conditions.
Points: 175
Balance the equation: N₂ + H₂ → NH₃
Answer: N₂ + 3H₂ → 2NH₃
Points: 150
What is a hypothesis?
Answer: A hypothesis is a testable prediction about the possible outcome of an investigation.
Points: 50
Students compare paper bags made with different amounts of banana fiber. Why must all the paper bags have the same size and drying time?
Answer: These variables must be controlled to ensure that the strength of the bags is compared fairly.
Points: 125
What are the starting substances and newly formed substances in a chemical reaction called?
Answer: The starting substances are reactants, while the newly formed substances are products.
Points: 50
Students investigate whether the amount of calamansi extract in a homemade cleaning spray affects how much stain it removes. What is the dependent variable?
Answer: The amount of stain removed by the cleaning spray
Points: 75
Who proposed the Continental Drift Theory?
Answer: Alfred Wegener
Points: 50
Balance the equation: Mg + O₂ → MgO
Answer: 2Mg + O₂ → 2MgO
Points: 100
When baking soda reacts with vinegar, bubbles are produced. What evidence of a chemical reaction is shown?
Formation of gas
Points: 100
What two major geological features commonly form when an oceanic plate sinks beneath another oceanic plate?
Answer: A deep-ocean trench and a volcanic island arc
Points: 125
Balance the equation: Al + O₂ → Al₂O₃
Answer: 4Al + 3O₂ → 2Al₂O₃
Points: 200
Students investigate whether the amount of calamansi extract in a homemade cleaning spray affects how much stain it removes. What is the independent variable?
Answer: The amount of calamansi extract in the cleaning spray
Points: 75