Question

properties of water
write the definition of each key term.
polarity:
cohesion:
adhesion:
capillary action:
surface tension:
specific heat:
hydrogen bond:

1. circle the letter of each sentence that is true about waters structure.

a. water is made up of atoms bonded to form molecules.
b. water contains half as many hydrogen atoms as oxygen atoms.
c. water molecules tend to push away from each other.
d. the chemical formula for water is h₂o.

1. one side of the water molecule has a positive charge, while the other side has a negative charge. what do the charges indicate about the molecule?

a. water is a polar molecule.
c. water is an ionic compound.
b. water is a nonpolar molecule.
d. water is an ion.

1. bonds that form between water molecules are called bonds.
2. true or false? hydrogen bonds are strong and require a lot of energy to break.
3. the tendency for water molecules to stick to other water molecules is called
4. a force that acts on the particles of a liquid at the surface is called
5. how does surface tension force the surface of water to curve?

Explanation:

• Polarity: Uneven charge distribution in a molecule. In water, oxygen is more electronegative, creating a partial - negative and partial - positive side.
• Cohesion: The attraction between like molecules. In water, hydrogen bonds hold water molecules together.
• Adhesion: The attraction between unlike molecules. Water can stick to other substances like glass.
• Capillary action: The combined force of cohesion and adhesion that allows water to move up a narrow tube against gravity.
• Surface tension: A measure of how difficult it is to stretch or break the surface of a liquid. Caused by cohesive forces among water molecules at the surface.
• Specific heat: The amount of heat energy required to raise the temperature of a given quantity of a substance by 1 degree Celsius. Water has a high specific heat.
• Hydrogen bond: A weak bond between the hydrogen atom of one molecule and a highly electronegative atom (like oxygen) of another molecule.
• For question 1: a. True - Water is H₂O, made of hydrogen and oxygen atoms bonded into molecules. d. True - The chemical formula for water is H₂O.
• For question 2: a. Water is a polar molecule due to the charge separation.
• For question 3: Hydrogen.
• For question 4: False - Hydrogen bonds are relatively weak.
• For question 5: Cohesion.
• For question 6: Surface tension.
• For question 7: The cohesive forces between water molecules at the surface pull inward, creating a tension that causes the surface to curve.

Answer:

• Polarity: Uneven charge distribution in a molecule.
• Cohesion: Attraction between like molecules.
• Adhesion: Attraction between unlike molecules.
• Capillary action: Movement of water up a narrow tube against gravity due to cohesion and adhesion.
• Surface tension: Difficulty in stretching or breaking the liquid surface due to cohesive forces at the surface.
• Specific heat: Heat energy needed to raise the temperature of a substance by 1°C.
• Hydrogen bond: Weak bond between hydrogen of one molecule and a highly electronegative atom of another.
• Question 1: a. Water is made up of atoms bonded to form molecules., d. The chemical formula for water is H₂O.
• Question 2: a. Water is a polar molecule.
• Question 3: Hydrogen
• Question 4: False
• Question 5: Cohesion
• Question 6: Surface tension
• Question 7: Cohesive forces between surface - water molecules pull inward, causing the surface to curve.