Why water matters for life: cohesion, adhesion, heat and ice

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. Read this first

   Use this

   Read-about card, not to scale. Water moves from the roots to the leaves through xylem tubes. Water leaving the leaves pulls the water column upward. Water molecules cling to each other and to the xylem walls.

2. 1.

   Pia reads that water reaches the top of a 116-meter tree. Which claim and reason explain how water moves up the xylem?

   • Water is pulled up as one column: adhesion links the molecules and cohesion holds them to the xylem walls
   • Water is pulled up as one column: nonpolar water slides along the xylem walls without sticking
   • Water is pulled up as one column: covalent bonds link each molecule to the next in the tube
   • Water is pulled up as one column: cohesion links the molecules and adhesion holds them to the xylem walls
3. 2.

   Tala reads how ice thickens on a pond. Which claim and reason explain why the ice grows more slowly each day?

   • The ice grows more slowly, because the ice on top insulates the water below
   • The ice grows more slowly, because the air warms up each day
   • The ice grows more slowly, because the pond is running out of water
   • The ice grows more slowly, because new ice is denser and sinks away from the top

4. Use this

   Investigation card. Question: Does a coin hold more water drops on its heads side or its tails side? Changed: which side of the coin faces up. Measured: drops added with a dropper before the dome of water spills. Kept the same: the dropper, the water, the table. Results table: Side | Coin used | Drops before spilling; heads | dime | 14; tails | penny | 20. model data.

5. 3.

   A dome of water on a coin is held by cohesion. Zee reads this class test. How should the test be fixed?

   • Use a bigger dropper on the tails side
   • Use colder water for the tails side
   • Use the same coin for both sides, so only the side changes
   • Count the drops after the water spills, not before

6. Use this

   Investigation card. Question: Does the kind of paper change how high water climbs a dipped strip? Changed: the kind of paper. Measured: how many centimeters the water climbed in 5 minutes. Kept the same: strip width of 2 cm, the cup, the water, the time. Results table: Paper | Dipped depth (cm) | Climb (cm); paper towel | 1 | 7; printer paper | 3 | 3. model data.

7. 4.

   Ari reads a test of water climbing paper strips. What is the flaw in the test?

   • The water should have been warmer for the printer paper
   • The strips were dipped to different depths, so depth changed too
   • The time was too short for the water to climb
   • The strips were cut to different widths, so width changed too

8. Use this

   Investigation card. Question: Which warms more under a lamp, water or sand? Changed: the material. Measured: the temperature rise after 5 minutes. Kept the same: the lamp, its distance, the start temperature. Results table: Material | Mass (g) | Rise (°C); water | 400 | 4; sand | 100 | 12. model data.

9. 5.

   Bo reads a lamp test on water and sand. What is the flaw in the test?

   • The lamp should have been closer to the water
   • The masses differed, so the rises cannot be compared fairly
   • The start temperatures should have been different
   • Water has a high specific heat, so it should have warmed more
10. 6.

    Esme reads that a tub of water took in 2,400 calories and warmed from 15 °C to 21 °C. At 1 calorie per gram per °C, what mass is the water?

    • 14,400 g
    • 400 g
    • 114 g
    • 2,400 g
11. 7.

    To carry 1,172 calories of heat away from skin, how much sweat must evaporate at 586 calories per gram, and how does the skin change, Jun?

    • 2 g of sweat; the skin cools
    • 586 g of sweat; the skin cools
    • 0.5 g of sweat; the skin cools
    • 2 g of sweat; the skin warms
12. 8.

    A 100 g sample takes in 600 calories and warms 30 °C, Kira reads. Water needs 1 calorie per gram per °C; sand needs about one fifth of that. What is it?

    • Water: it needs 6 calories per gram per °C
    • Sand: it needs 20 calories per gram per °C
    • Sand: it needs about 0.2 calorie per gram per °C
    • Water: a high specific heat means it warms the most
13. 9.

    model data, a pond in winter. Luz reads pond temperatures under the ice. The warmest water, at 4 °C, is at the bottom. Why is the warmest water at the bottom?

    • Ice is denser than liquid water, so it sinks and pushes the warm water down
    • Heat flows down from the ice, so the bottom gets the most heat
    • Water near 4 °C is denser than colder water, so it sinks to the bottom
    • Hydrogen bonds pull heat down toward the bottom
14. 10.

    “not to scale” Noah wraps a wet cloth around a thermometer bulb in a breeze. The cloth water starts at room temperature, 25 °C. The reading falls to 20 °C. Why?

    • Evaporation breaks covalent bonds inside the water molecules, and that takes heat
    • Evaporation takes heat away from the bulb and the cloth
    • Evaporation adds heat to the bulb, so the cooling comes from the breeze itself
    • The cloth water is colder than the room, so it cools the bulb