7th Grade Science Vocabulary

7th Grade Science Vocabulary Words

  • Cell

    • Definition: The smallest unit of life that makes up living things.

    • Note: Cells are the basic building blocks of all living organisms, from single-celled bacteria to multi-cellular plants and animals.

  • Atom

    • Definition: The tiny building block of all matter.

    • Note: Atoms consist of a nucleus (made of protons and neutrons) surrounded by electrons.

  • Molecule

    • Definition: A group of atoms bonded together.

    • Note: Molecules can consist of two or more atoms of the same element (e.g., O2_2) or different elements (e.g., H2_2O).

  • Force

    • Definition: A push or pull on an object.

    • Note: Forces can be contact forces (like friction) or non-contact forces (like gravitational force).

  • Energy

    • Definition: The ability to do work or cause change.

    • Note: Energy can exist in various forms, such as kinetic, potential, thermal, chemical, and electrical.

  • Ecosystem

    • Definition: A community of living and nonliving things interacting.

    • Note: Ecosystems encompass various environments including forests, oceans, and deserts, and involve interactions between organisms and their physical surroundings.

  • Photosynthesis

    • Definition: How plants use sunlight to make food.

    • Note: The general equation for photosynthesis is:
      6CO2+6H2O+extlightenergy<br>ightarrowC6H12O6+6O26CO_2 + 6H_2O + ext{light energy} <br>ightarrow C_6H_{12}O_6 + 6O_2

    • Explanation: Plants convert carbon dioxide and water into glucose (a sugar used for energy) and oxygen in the presence of sunlight.

  • Gravity

    • Definition: The force that pulls objects toward each other.

    • Note: Gravity is a universal force that affects all masses and is responsible for the attraction of objects toward the Earth and other celestial bodies.

  • Chemical Reaction

    • Definition: A process where substances change into new substances.

    • Note: Chemical reactions involve the breaking of chemical bonds in reactants and the formation of new bonds in products. They can be categorized as exothermic or endothermic depending on energy transfer.

  • Density

    • Definition: How much mass is packed into a certain amount of space.

    • Note: Density is calculated using the formula:
      extDensity=racextmassextvolumeext{Density} = rac{ ext{mass}}{ ext{volume}}

    • Example: If an object has a mass of 10 grams and occupies a volume of 2 cm³, its density would be 5 g/cm³.