Working Scientifically Flashcards

Bunsen Burner Flames

• Air Hole Settings: Adjust to control the flame type.

  • Open Air Hole: Increases oxygen supply, producing a blue flame (roaring flame).

  • Half-Open Air Hole: Moderate oxygen supply, produces a balanced flame.

  • Closed Air Hole: Reduces oxygen supply, producing a yellow (safety) flame.

• Types of Flames:

  • Roaring Flame:

  • Used for: Strong heating, suitable for experiments requiring high temperatures.

  • Appearance: Blue flame, indicating complete combustion due to sufficient oxygen.

  • Blue Flame:

  • Used for: Heating substances slowly, more control over the heating process.

  • Appearance: Also blue but less intense than roaring flame, indicating moderate combustion.

  • Safety Flame:

  • Used for: When the Bunsen burner is on but not actively in use; safer to avoid fire hazards.

  • Appearance: Yellow flame, indicating incomplete combustion and reduced heat output.

Types of Variables in Experiments

• Independent Variable:

  • Definition: The single variable that you change in an experiment.

  • Notes: Only one should be altered to ensure clarity in results.

• Dependent Variable:

  • Definition: The variable that changes as a result of the independent variable.

  • Notes: It is what you measure in the experiment.

• Controlled Variables:

  • Definition: Other factors that must remain constant throughout the experiment to ensure a fair test.

  • Notes: Ensuring these are unchanged is crucial for valid results.

The Scientific Method

• Definition: A systematic approach for investigating observations and questions.

  • Steps of the Scientific Method:

  1. Observation: Note something of interest.

  2. Question: Formulate a question based on the observation.

  3. Hypothesis: Propose a possible explanation needing testing.

  4. Experiment: Conduct the experiment to test the hypothesis.

  5. Results: Collect and analyze data from the experiment.

  6. Conclusion: Determine if the hypothesis was correct based on the results.

  7. Share Findings: Present the findings to others.

  8. Evaluation: Reflect on the experiment and suggest improvements for future investigations.

Hazard Symbols

• Hazard Symbols and their Meanings:

  • Explosive:

  • Meaning: Substance can explode if not handled correctly.

  • Harmful/Irritant:

  • Meaning: Can cause skin redness or blistering but not corrosive.

  • Corrosive:

  • Meaning: Can damage skin or eyes upon contact.

  • Highly Flammable:

  • Meaning: Substance catches fire easily.

  • Toxic:

  • Meaning: Can cause significant harm to the environment; particularly toxic to aquatic life.

  • Health Hazard:

  • Meaning: Substances that are dangerous to health and potentially life-threatening.

  • Oxidising Agent:

  • Meaning: Provides oxygen to support the burning of other substances more fiercely.