Properties and Behavior of Water

This lecture introduces the essential role of water in life, highlighting its importance in cellular structure and function. It explains water's unique molecular structure, focusing on electronegativity and polarity, which lead to hydrogen bonding. These bonds, though weak, are crucial for water's properties and interactions.

What percentage of the Earth's surface is covered by water?

• 90%

• 34%

• 50%

• 75%

Why is water essential for cellular function?

• It acts as a waste product.

• It is a source of vitamins.

• It maintains cellular shape and participates in chemical reactions.

• It provides energy to cells.

What is the shape of a water molecule?

• Square

• V-shaped

• Tetrahedral

• Linear

Which atom in a water molecule is more electronegative?

• Hydrogen

• Both are equally electronegative

• Oxygen

• Neither

What happens to the electrons in a water molecule due to electronegativity?

• They are equally shared between hydrogen and oxygen.

• They spend more time around the hydrogen atoms.

• They are lost to the environment.

• They spend more time around the oxygen atom.

What causes a water molecule to be polar?

• Equal sharing of electrons

• Unequal sharing of electrons

• Presence of ionic bonds

• Absence of hydrogen bonds

What type of bond forms between water molecules?

• Covalent bond

• Ionic bond

• Metallic bond

• Hydrogen bond

What is the result of the polarity of water molecules?

• Water molecules become non-polar.

• Water molecules attract each other.

• Water molecules repel each other.

• Water molecules lose their shape.

How do hydrogen bonds in water behave in liquid form?

• They are strong and permanent.

• They are weak and constantly forming and breaking.

• They do not form at all.

• They are stronger than covalent bonds.

What is the duration of a hydrogen bond in liquid water?

• A few seconds

• A few minutes

• A few trillions of a second

• A few hours