A. Objective The learners should be able to investigate changes that happen in the absence of oxygen. B. Materials ● fire. Activity: TITLE: ABSENCE OF OXYGEN Jar with cover (Jar A) Jar without cover (Jar B) 2 same sized candle (small) Match or lighter Timer Ruler C. Precautionary Measure Remember to handle match or lighter carefully and don't play with it for it can cause D. Procedure 1. Label the jar with cover with Jar A and the jar without cover as Jar B. 2. Light the candles with a match and put the candles in each jar. 3. Record the time when the candles are lighted and the time when the light was put off. 4. Cover the Jar A and observe what will happen. 5. Measure the length of the candles after the flame was put off. 6. Record your findings on the chart below. Jars JAR A JAR B Time of the flame was put off Length of the candle after burning Answer the following questions: 1. Which of the 2 jars was the candle's flame put off first? 2. Which of the two candles has the shortest size? 3. What happen, when you cover the Jar A? 4. When the lighted candle in Jar A was covered, the flame was put off, what is the reason why the candle's flame did not continue to burn? 5. What are the 3 main components in combustion? Doss​

When Patrick went for an interview in his On-the-Job Training in a 20-floor building, he was about to take an elevator but noticed that Elevator A only caters to even-numbered floors and the Elevator B can only go to odd-numbered ones. However, the two elevators both cater the four underground floors. How would you represent the floors serviced by the two elevators as sets? (Use U1, U2, U3, U4 for the underground floors, and use A and B to denote the sets.)?​

Answer:

The floors serviced by elevator A can be represented as the set A = {2, 4, 6, 8, ..., 18, 20}.

The floors serviced by elevator B can be represented as the set B = {1, 3, 5, 7, ..., 19}.

The four underground floors can be represented as the set U = {u1, u2, u3, u4}.

Therefore, the complete set of floors serviced by the two elevators can be represented as the union of the sets A, B, and U: A ∪ B ∪ U.