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What did Marshall and Warren discover?
They found that H. pylori bacteria cause most stomach ulcers.
What did van Helmont show in his plant experiment?
He showed that plants gain mass mostly from water, not soil.
What did Percy Spencer discover?
He discovered microwave heating after a chocolate bar melted near a magnetron.
How did Marshall and Warren use observation?
They saw bacteria in stomach samples and linked them to ulcers.
How did van Helmont use observation?
He noticed the plant grew a lot but the soil barely changed in mass.
How did Spencer use observation?
He noticed his chocolate bar melted unexpectedly and investigated why.
What new technology came from Spencer’s discovery?
The microwave oven.
Why did doctors doubt Marshall and Warren at first?
They believed ulcers were caused by stress and acid, not bacteria.
Why didn’t van Helmont understand how plants really gained mass?
He didn’t know about photosynthesis or carbon dioxide.
Why is Spencer considered a scientist without formal training?
He used experiments and evidence to test ideas.
What was Marshall and Warren’s hypothesis and conclusion?
Hypothesis: Bacteria cause ulcers. Conclusion: H. pylori causes ulcers and can be treated with antibiotics.
What was van Helmont’s hypothesis and conclusion?
Hypothesis: Plants gain mass from water. Conclusion: Plants don’t gain mass from soil; most comes from something else (later known as CO₂).
What was Spencer’s hypothesis and conclusion?
Hypothesis: Magnetrons can heat food. Conclusion: Microwave energy cooks food quickly.
Why do new or unusual ideas take time to be accepted?
People trust old ideas and need strong proof to change their beliefs.
