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

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Use this

   Side view of a water drop on a plate, not to scale. The drop is a round dome. Water molecule beads inside the dome are joined to neighbors by dashed hydrogen bonds.

2. 1.

   Kira sets a drop of water on a smooth plate. It stays in a round dome instead of spreading flat. What holds the dome together?

   • Cohesion, from covalent bonds between water molecules
   • Adhesion, from water molecules sticking to the plate
   • Cohesion, since nonpolar molecules clump together
   • Cohesion, from hydrogen bonds between water molecules
3. 2.

   Luz sees water climb inside a thin glass tube, higher at the walls than in the middle. Which attraction pulls it up the walls?

   • Evaporation: water molecules leave the middle and rise
   • Adhesion: nonpolar water slides up the glass
   • Adhesion: water molecules are drawn to the glass walls
   • Cohesion: water molecules are drawn to the glass walls
4. 3.

   not to scale. A water strider rests on Milo's school pond without sinking. What explains why the water surface holds it up?

   • Surface tension, from covalent bonds inside each water molecule
   • Adhesion, from water sticking to the strider's legs
   • Surface tension, since nonpolar water bunches at the top
   • Surface tension, from hydrogen bonds between surface molecules
6. 4.

   Noah's class heated water and sand under one lamp. Which warmed faster, and what does that say about its specific heat?

   • Sand; it has the lower specific heat
   • Water; it has the lower specific heat
   • Sand; it has the higher specific heat
   • Water; it has the higher specific heat
7. 5.

   By minute 6, the sand's temperature had risen how many times as much as the water's, Pia?

   Use the picture in question 4.

   • 12 times as much
   • about 1.5 times as much
   • one fifth as much
   • 5 times as much
8. 6.

   model data. Tala gives 500 calories to 100 g of water and 500 calories to 100 g of sand. The water warms 5 °C. How much does the sand warm?

   • 1 °C
   • 5 °C
   • 100 °C
   • 25 °C
9. 7.

   5 g of the water in a runner's sweat evaporates. Evaporating 1 g of water takes 586 calories. What happens to the skin, Zee?

   • 591 calories leave the skin; the skin cools
   • 586 calories leave the skin; the skin cools
   • 2,930 calories enter the skin; the skin warms
   • 2,930 calories leave the skin; the skin cools
10. 8.

    Ari's teacher warms 80 g of water from 20 °C to 35 °C. Water needs 1 calorie per gram per °C. How much heat does the water take in?

    • 1,200 calories
    • 15 calories
    • 95 calories
    • 2,800 calories
11. 9.

    Side view of a pond on a cold night, not to scale. A pond begins to freeze on a cold night near Bo's home. Where does the ice form, and what does it do?

    • At the bottom; the deep water is the coldest
    • At the top; it traps cold air against the water below
    • At the top; it floats and insulates the water below
    • At the bottom; it is denser and sinks, leaving the top liquid
12. 10.

    USGS values. Esme compares 100 g of ice with 100 g of liquid water. Which takes up more space, and why?

    • The ice, because its molecules sit farther apart
    • Both the same, because both have a mass of 100 g
    • The ice, because it has more molecules
    • The liquid water, because ice molecules are packed tighter