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Science Test #7 Flashcards

6 cards from real GED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Science Test #7 flashcards as text

  1. What process do plants use to convert carbon dioxide and water into glucose using sunlight?

    Answer: Photosynthesis

    Photosynthesis is the process by which plants, algae, and some bacteria use light energy (usually from the sun) to convert carbon dioxide and water into glucose and oxygen.

  2. A substance has a pH of 2. How would you classify this substance?

    Answer: Strongly acidic

    The pH scale runs from 0 to 14. A pH of 7 is neutral, values below 7 are acidic, and values above 7 are basic. A pH of 2 indicates a strongly acidic substance.

  3. Which layer of the atmosphere contains the ozone layer that protects Earth from ultraviolet radiation?

    Answer: Stratosphere

    The ozone layer is located in the stratosphere, approximately 15–35 km above Earth's surface. It absorbs most of the sun's harmful ultraviolet (UV) radiation, protecting life on Earth.

  4. In an experiment, a scientist changes only one variable while keeping all others constant. The variable that is changed is called the:

    Answer: Independent variable

    The independent variable is the one that the scientist deliberately changes or manipulates in an experiment to observe its effect. The dependent variable is what is measured in response to those changes.

  5. Which of the following is an example of a physical change rather than a chemical change?

    Answer: Dissolving sugar in water

    Dissolving sugar in water is a physical change because no new substance is created — the sugar molecules remain unchanged and can be recovered by evaporating the water. The other options all involve chemical reactions that create new substances.

  6. What is the primary cause of the seasons on Earth?

    Answer: The tilt of Earth's axis as it orbits the Sun

    Earth's seasons are caused by the 23.5-degree tilt of Earth's axis relative to its orbital plane. As Earth orbits the Sun, this tilt causes different hemispheres to receive more direct sunlight at different times of year.