CAAT - Canadian Adult Achievement Basic Scientific Principles Questions and Answers — Questions and Answers
Question 1: When a person turns on a standard incandescent lamp, what is the primary energy transformation that occurs?
- Chemical energy to light energy
- Electrical energy to light and heat energy (Correct answer)
- Mechanical energy to electrical energy
- Nuclear energy to heat energy
Correct answer: Electrical energy to light and heat energy
A lamp plugs into a wall socket, which supplies electrical energy. This electricity flows through the bulb's filament, causing it to glow and produce light. A significant amount of this energy is also lost as heat, which is why the bulb becomes hot.
Question 2: In most ecosystems, what is the primary role of organisms classified as 'producers'?
- To break down dead organic matter into nutrients
- To convert sunlight into chemical energy through photosynthesis (Correct answer)
- To consume other organisms for energy
- To regulate the population of herbivores
Correct answer: To convert sunlight into chemical energy through photosynthesis
Producers, such as plants and algae, form the base of the food web. They are unique in their ability to perform photosynthesis, a process that uses sunlight to convert carbon dioxide and water into glucose (a form of chemical energy) and oxygen.
Question 3: A student leaves an open glass of cold water on a table in a warm room. A few hours later, tiny droplets of water have formed on the outside of the glass. Which scientific process best explains this observation?
- Evaporation
- Precipitation
- Condensation (Correct answer)
- Transpiration
Correct answer: Condensation
Condensation is the process where water vapor (a gas) in the air turns into liquid water. The air in the warm room contains invisible water vapor. When this warm, moist air comes into contact with the cold surface of the glass, it cools down, causing the water vapor to change its state into liquid droplets on the outside of the glass.
Question 4: A scientist is testing the effect of different types of soil on the growth of bean plants. She plants identical bean seeds in three separate pots. Pot A contains sandy soil, Pot B contains clay soil, and Pot C contains loam soil. All pots are given the same amount of water and sunlight. She measures the height of the plants every week. What is the independent variable in this experiment?
- The type of soil (Correct answer)
- The amount of water
- The height of the plants
- The amount of sunlight
Correct answer: The type of soil
The independent variable is the one factor that the experimenter intentionally changes or manipulates to observe its effect. In this experiment, the scientist is deliberately using different types of soil to see how they affect plant growth. The factors kept the same (water, sunlight) are controls, and the factor being measured (plant height) is the dependent variable.
Question 5: A heavy box is sitting motionless on a flat floor. Which statement best explains why the box is not moving?
- There are no forces acting on the box.
- The force of gravity is weaker than the force of friction.
- The downward force of gravity and the upward force from the floor are balanced. (Correct answer)
- The box has too much inertia to be affected by gravity.
Correct answer: The downward force of gravity and the upward force from the floor are balanced.
According to Newton's First Law of Motion, an object at rest will stay at rest if the net force acting on it is zero. The Earth's gravity pulls the box down, while the floor exerts an equal and opposite upward force (called the normal force). Because these two forces are equal in magnitude and opposite in direction, they cancel each other out, resulting in balanced forces and no movement.
Question 6: Which of the following is an example of a chemical change?
- Boiling water to make steam
- Chopping wood into smaller pieces
- A metal nail rusting in the rain (Correct answer)
- Melting an ice cube
Correct answer: A metal nail rusting in the rain
A chemical change results in the formation of a new substance with different properties. When an iron nail rusts, the iron reacts with oxygen and water in the environment to form iron oxide (rust), which is a new chemical compound. The other options are physical changes, where the substance's form changes but its chemical identity does not.
CAAT - Canadian Adult Achievement Basic Scientific Principles Questions and Answers
When a person turns on a standard incandescent lamp, what is the primary energy transformation that occurs?