8Science9 Task 2 Flashcards

Structure and Properties of Matter

  • Elements, Compounds, and Mixtures:

    • Element: A substance made of only one type of atom.

    • Compound: A substance made up of two or more different elements chemically bonded together.

    • Mixture: A substance consisting of two or more substances not chemically combined together.

  • Periodic Table:

    • Symbols for elements are internationally recognized to provide a common language (e.g., Oxygen = O, Hydrogen = H).

    • Metals are located on the left side of the periodic table.

    • Non-metals are located on the right side of the periodic table.

  • Properties and Uses of Common Elements:

    • Copper (Cu): Shiny, bronze, ductile, conducts electricity, metal.

    • Sulfur (S): Yellow, brittle, dull, doesn’t conduct electricity, non-metal.

  • Developing Aims and Hypotheses:

    • Aim: To investigate the effect of (IV) on (DV).

    • Hypothesis: As (IV) increases/decreases, (DV) increases/decreases at a … rate because (scientific theory).

  • Technological Devices for Understanding Structure:

    • STM (Scanning Tunneling Microscopy): Enables us to see the atomic structure of elements.

    • TEM (Transmission Electron Microscope): Creates a 3D or closer image of objects such as viruses and proteins.

  • Chemical Formulae and Common Names:

    • NaCl = Sodium Chloride

    • CuSO4CuSO_4 = Copper Sulfate

    • HCl = Hydrochloric Acid

    • CaCO3CaCO_3 = Calcium Carbonate

    • CO2CO_2 = Carbon Dioxide

    • H2OH_2O = Water

    • H₂SO₄ = Sulfuric Acid

    • NaOH = Sodium Hydroxide

  • Chemical Change vs. Physical Change:

    • Risk Assessment: Identify the hazard, assess the risk, identify precaution/control measures, and outline disposal methods (for chemicals only).

  • Distinguishing Between Physical and Chemical Changes:

    • Chemical Change: Creates new substances.

    • Physical Change: Alters the form and state of the substance, but the number of particles remains the same.

  • Identifying Chemical Reactions:

    • Chemical reactions can be identified by observing changes in temperature, the appearance of a new substance, or the disappearance of the original substance.

  • Examples of Chemical Change in Everyday Life:

    • Photosynthesis: Plants convert carbon dioxide and water into glucose and oxygen using sunlight.

    • Rusting of iron: Iron reacts with oxygen and water to form iron oxide (rust).

Cells Structure and Function

  • Living Things and Cells:

    • All living things are made of cells, which are the basic unit of life.

    • Some living things are unicellular (e.g., bacteria), while others are multicellular (e.g., animals, plants).

    • Cells perform all the functions necessary to keep a living thing alive (MRS GREN).

  • Characteristics of Living Things (MRS GREN):

    • M - ovement: Ability of organisms to move.

    • R - espiration: Set of chemical reactions taking place in cells.

    • S - ensitivity + control: Ability to detect/respond to changes in internal/external environment.

    • G - rowth: Permanent increase in dry mass & size.

    • R - eproduction: Process of producing more of the same organism.

    • E - xcretion: Removal of waste products of metabolism.

    • N - utrition: Taking in materials for energy.

  • Using a Light Microscope:

    • Place the slide on the stage and use clips to hold it in place.

    • Start with the lowest objective lens.

    • Look through the eyepiece and use the coarse focus knob to bring the image into view.

    • Use the fine focus knob to sharpen the image.

    • Adjust the light source or mirror if it’s too dark.

  • Animal and Plant Cell Structures:

    • Key structures include the nucleus, cytoplasm, cell membrane, cell wall, chloroplast, vacuole, and mitochondria.

  • Functions of Cell Structures:

    • Nucleus: Controls the cell’s activities and contains DNA.

    • Cytoplasm: Jelly-like fluid where chemical reactions happen.

    • Cell membrane: Controls what goes in and out of the cell.

    • Mitochondria: Where energy is released in respiration.

    • Cell wall (plants only): Made of cellulose; gives strength and structure.

    • Chloroplasts (plants only): Where photosynthesis happens; contains chlorophyll to absorb light.

    • Permanent vacuole (plants only): Contains cell sap; helps support the cell.

  • Preparing a Wet Mount Slide of Onion Cells:

    • Peel a thin layer of onion skin (epidermis) using tweezers.

    • Place the onion skin flat onto a clean microscope slide.

    • Add a drop of iodine stain to make the cells more visible.

    • Lower a cover slip gently over the onion skin using a needle or tweezers to avoid air bubbles.

    • Blot any excess iodine with paper towel if needed.

    • Observe under a light microscope, starting with the lowest magnification.

  • Skill: Create biological drawings of animal and plant cells.