Question: What observation can Riya record and why is recording useful?
Answer: Riya should record that the desk surface became sticky after juice spillage and that dust sticks more to the sticky area. Recording is useful because it provides evidence of the change and helps identify the cause (juice residue), which can be cleaned to prevent dust accumulation.

Question: What is the variable in this experiment and what conclusion can be drawn?
Answer: The variable is sunlight (amount of light). Conclusion: Plants receiving more sunlight grew taller, suggesting sunlight helps plant growth (photosynthesis), keeping other conditions same.

Question: What scientific idea does this observation illustrate?
Answer: This illustrates evaporation: water changes from liquid to vapor faster when sunlight (heat) is present. Observing environmental change helps understand the effect of temperature on evaporation.

Question: What skill does this activity teach and how is it useful?
Answer: It teaches classification based on properties (absorbent vs non-absorbent). This skill helps students organise materials and choose appropriate ones for tasks, like using sponges for cleaning spills.

Question: What kind of observation is this and why are tools used?
Answer: This is a qualitative observation (description of texture and appearance) aided by a tool. Tools like magnifiers extend our senses and reveal details not visible to the naked eye.

Question: How should students present their data and what does the data show?
Answer: Students should use a table with temperature and time columns. The data typically shows sugar dissolves faster in hot water, demonstrating the effect of temperature on dissolving rate.

Question: Why do some materials feel colder and how can students investigate this?
Answer: Materials like metal feel colder because they conduct heat away from the hand faster. Students can compare by touching different materials and noting sensations; further, they can measure temperature with a thermometer to compare objectively.

Question: What process causes browning and how can it be tested?
Answer: Browning is due to oxidation. To test, place apple pieces in water and lemon juice; the one in lemon juice browns slower due to acid slowing oxidation. Recording observations supports the explanation.

Question: What is a reasonable prediction and how would you test it?
Answer: Prediction: The object will rise to the surface when released because buoyant force pushes it up. Test by pressing a small plastic ball under water and releasing, observing its motion.

Question: Which factors affect drying and what conclusion can be drawn?
Answer: Factors: wind speed, temperature, humidity. Conclusion: Increased airflow (wind) speeds evaporation, drying cloth faster, demonstrating environmental influence on physical changes.

Question: How does this activity help scientific understanding?
Answer: It develops observation and classification skills and helps students link material properties (transparent, rigid, flexible) to their uses in daily life.

Question: What inference can students make and what additional information would make the conclusion stronger?
Answer: Inference: Watering helps seedling growth. Stronger conclusion needs repeated trials and control of other factors (soil type, sunlight) to ensure water is the cause.

Question: What causes the shadow to change and how can this be used as an observation activity?
Answer: The sun's position changes during the day, changing shadow length. Students can record shadow length at different times to connect sun angle with shadow size.

Question: Why is this classification important and how does it relate to 'change around us'?
Answer: It helps in waste management; biodegradable items decompose naturally while non-biodegradable do not. Understanding decomposition is part of studying changes around us and environmental science.

Question: What is happening and what precaution can prevent it?
Answer: The spoon is rusting (oxidation of metal). To prevent rust, keep metal items dry, apply protective coatings or store indoors.

Question: Explain this observation using particle idea of matter in simple terms.
Answer: Warmth from hands increases particle motion in ice causing particles to break free into liquid form faster. Higher temperature speeds up melting.

Question: What factors might cause bread to become stale and how does sealing help?
Answer: Exposure to air causes moisture loss and staling; sealing reduces air contact and moisture loss, slowing changes.

Question: What property are they testing and why is repeating drops important?
Answer: They test elasticity (ability to regain shape). Repeating drops ensures consistent results and reduces error due to one-off factors like surface irregularities.

Question: How can students investigate this behaviour scientifically?
Answer: Students can observe which plants respond, record conditions, and research plant types (e.g., touch-sensitive plants like Mimosa pudica). Controlled experiments can test factors like light and touch intensity.

Question: Suggest how to measure 'cleaning effectiveness' and how to make the test fair.
Answer: Measure amount of oil removed or rate of removal (time taken with same soap amount and rubbing). To make fair, use same oil, same quantity of soap, same rubbing time and similar plates.