Practice Test 12 - 5th Grade Science
20 questions. Answer them in any order, then submit to see your score and every explanation.
- In a forest, mushrooms and bacteria decay a fallen log; why are decomposers important?
- The student recorded observations for mixing oil and water but forgot one important part. Based on the notes below, what additional observation would best help compare before and after mixing? Student notes (Diego, Oct. 15): - After stirring for 20 seconds, the cup had two layers. - The top layer was yellow and the bottom layer was clear. - No bubbles were seen.
- The model shows sugar moves to other parts; for long-term storage plants make what?
- The explanation says sugar stores energy in its chemical bonds; this energy came from what?
- A student says, "A new substance formed because the mixture got warmer." In the investigation, students mixed 100 mL of cold water (10°C) with 100 mL of hot water (50°C). The final temperature was 30°C, and there were no bubbles, no new smell, and no solid formed. Based on the evidence, is the student's reasoning correct?
- The table compares properties before and after mixing sugar and water. Before mixing: - Sugar: white crystals, Solid, 22°C, no smell - Water: clear, Liquid, 22°C, no smell After mixing: - Sugar water mixture: clear, Liquid, 22°C, no smell, no visible crystals How can you tell this is a physical change and not a chemical change?
- Most plant mass (~93%) comes from air/water; soil adds ~7% minerals. Which matches?
- The table compares properties of two original substances before mixing and the mixture after mixing (salt + water). Which property changed when the substances were mixed? Before mixing: - Salt: white, Solid, no smell, grainy - Water: clear, Liquid, no smell, 22°C After mixing (salt water): clear, Liquid, no smell, 22°C, no visible salt grains
- Looking at what happened when different substances were mixed, a student noticed that temperature sometimes matters. Cup A: Yeast + sugar + cold water. Observations after 10 minutes: a few small bubbles, little smell. Cup B: Yeast + sugar + warm water. Observations after 10 minutes: many bubbles, a stronger bread-like smell. Comparing these mixtures, what does this show about factors that affect whether new substances form?
- Gravity is a force. Which best describes what gravity does to objects near Earth?
- When you drop a pencil, it starts falling right away. What does this show about gravity?
- In a model, plants take in CO2 and release oxygen; how do biosphere and atmosphere interact?
- Emma examined a glass marble that was clear, very smooth, shiny, hard (could not scratch it with a fingernail), cool to the touch, and sank in water. What observable property helps describe this material?
- A bean plant kept in sunlight but not watered wilted; based on this, which materials are required for growth?
- Chen weighed 40 g salt in a sealed bag, then 40 g after crushing it; explain why.
- Looking at the measurements, what conclusion can you draw about weight during mixing?
- Sofia used a magnet and the rock did not stick. Which physical property was described?
- Keisha gathers community conservation facts; which sources show different perspectives on the same program?
- What pattern does this data show about Earth's water distribution by percentage?
- The data show Orion in winter and Scorpius in summer; what pattern is shown?