Iron nails are left outside. What two substances must be present for iron to rust?
Answer and explanation
Correct answer: A. Oxygen and water
- Step 1: Rusting is the reaction of iron with oxygen in the presence of water. Step 2. Both are needed. Answer: Oxygen and water. Why not the others: The other pairs are not the key requirements for rust.
Practise more Science and Technology Reasoning.
Free questions with an explanation for every one, and full timed ENLA Secondary Practice (Peru) mock tests.
More Science and Technology Reasoning questions
- In which part of a plant cell does photosynthesis take place?
- Which are the products of photosynthesis?
- In the food chain grass, grasshopper, frog, snake, the number of frogs falls sharply because of disease. What is the most likely short-term…
- In pea plants, tall (T) is dominant over short (t). Two plants with genotype Tt are crossed. What is the probability that an offspring is sh…
- What is the main function of red blood cells?
- Which of these organisms is a producer in a lake ecosystem?