Question

Observe a natural phenomenon or reaction.

Devise an explanation of what you have observed.
Experiment to support or refute your explanation.
Record the results of your experiments.
Determine whether your results support or refute your explanation.
Decide whether you need to rewrite your explanation or it has withstood testing.

Answer 1

1. The observed phenomenon is the formation of frost on windows during cold weather.

2. Explanation: Frost forms when moist air comes in contact with a cold surface, leading to condensation and freezing of water vapor.

3. Experiment: Placing a glass surface in a freezer and observing the formation of frost.

Step-by-step explanation:

Frost formation on windows during cold weather is a consequence of the fundamental principles of condensation and freezing. When warm, moist air encounters a cold surface, such as a window pane, the air's water vapor undergoes condensation, transforming into liquid water droplets. This occurs because cold air has a reduced capacity to hold moisture compared to warm air. As the temperature of the window surface decreases, the air near it also cools, causing the water vapor to transition from a gaseous state to a liquid state.

Subsequently, if the temperature drops further, the accumulated liquid water droplets freeze, leading to the crystalline structure characteristic of frost. This transition from liquid to solid occurs because the temperature has reached the freezing point of water, and the energy from the surrounding environment is insufficient to maintain the water in a liquid state. The intricate interplay between temperature, air moisture content, and the thermal properties of the window surface underlies this natural phenomenon, illustrating the dynamic nature of atmospheric processes.

Understanding the science behind frost formation not only explains a visually captivating occurrence but also has practical implications, contributing to advancements in insulation technology and energy-efficient building design.

Answer 2

1.Observation: A baking soda and vinegar reaction produces fizzing and bubbling when combined.

2.Explanation: When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), it forms carbon dioxide gas, leading to the release of bubbles and fizzing. This reaction occurs because the acetic acid in vinegar reacts with the sodium bicarbonate to produce carbonic acid, which rapidly breaks down into water and carbon dioxide gas.

3.Experiment: To support the explanation, I conducted an experiment by combining measured amounts of baking soda and vinegar in a closed container. I then observed and recorded the reaction.

4.Results: The reaction produced rapid bubbling and fizzing, filling the container with carbon dioxide gas, which escaped through an opening.

5.Evaluation: The results align with the explanation. The observed bubbling and fizzing are consistent with the formation and release of carbon dioxide gas due to the chemical reaction between baking soda and vinegar.

6.Conclusion: The explanation stands strong based on the experimental results, supporting the understanding that the reaction between baking soda and vinegar generates carbon dioxide gas, leading to the observed bubbling and fizzing.

Step-by-step explanation:

1.Observation: This natural phenomenon involves the reaction between baking soda (sodium bicarbonate) and vinegar (acetic acid), resulting in visible fizzing and bubbling.

2.Explanation: The reaction's chemical equation shows that when these substances combine, they create carbon dioxide gas, water, and a salt. This occurs because the acetic acid in the vinegar reacts with the sodium bicarbonate, forming carbonic acid. Carbonic acid rapidly breaks down into water and carbon dioxide gas, which creates the fizzing and bubbling seen during the reaction.

3.Experiment: To validate the explanation, I conducted an experiment. I measured specific amounts of baking soda and vinegar, mixed them in a closed container, and observed the reaction closely.

4.Results: The reaction produced vigorous bubbling and fizzing, indicating the release of carbon dioxide gas. The container's pressure increased, leading to gas escaping through an opening.

5.Evaluation: The observed reaction aligns with the predicted formation and release of carbon dioxide gas, consistent with the proposed explanation.

6.Conclusion: Based on the experimental results, the explanation remains valid. The observed reaction supports the understanding that the combination of baking soda and vinegar results in the production of carbon dioxide gas, validating the initial explanation.