Chemistry Of LIfe

Why does ice stay at the top of oceans instead of sinking to the bottom? 

• Ice is colder than liquid water

• Ice is less dense than liquid water

• Ice is more dense than liquid water

• Ice is warmer than liquid water

Water is often called the “universal solvent” because many substances can be dissolved in water. What property of water allows it to be such a universal solvent?

• Purity

• Polarity and cohesion

• High heat capacity

• Expansion upon freezing

Any compound that removes H+ ions to an aqueous solution and measures more than 7 on the pH scale:

• Base

• Solvent

• Acid

• Solute

Why does ice float?

• As water freezes, it expands and its density decreases.

• As water freezes, air becomes trapped between the hydrogen bonds of water molecules. 

• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have greater buoyancy (floating ability). 

• As water freezes, it takes up more oxygen from the atmosphere, causing it to have greater buoyancy.

Substance in a solution that dissolves the other substance and is present in the greater amount:

• Solute

• Acid

• Solution

• Solvent

The ability of water molecules to stick together is called:

• Adhesion

• Cohesion

• Transpiration

• Solvency

Water is polar because:

• The molecule has two poles, at which it is colder than the other regions of the molecule.

• The water molecule is neutral

• The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms. 

• The unequal sharing of electrons gives the water molecule a slight negative charge near its hydrogen atoms and a slight positive charge near its oxygen atom.

The bonds within a water molecule are:

• Polar covalent

• Hydrogen

• Ionic

• Non-polar covalent

Any compound that donates H+ ions to an aqueous solution and measures less than 7 on the pH scale:

• Acid

• Base

• Solvent

• Solute

Which of these is the smallest unit of living things?

• cells
• atoms 
• molecules
• compounds