At which one of the following temperatures is fresh water densest?

At 4°C temperatures is freshwater densest.

Key Points The density of water:

• At 39°F (or 3.98°C to be exact) water is the densest. This is because the molecules are closest together at this temperature.
• As the water cools it becomes denser.
• The closer the molecules, the heavier. The farther apart the molecules, the lighter.
• Density is just the weight for a chosen amount (volume) of the material.
• A common unit of measurement for water's density is gram per millilitre (1 g/ml) or 1 gram per cubic centimetre (1 g/cm3).
• Density varies with the changes in temperature
• 30°C is 0.9957 g cm-³
• 4°C is 1.0000 g cm-³
• 0°C is 0.9998 g cm-³

• Temperature (°F/°C)	Density (grams/cm3	Weight (pounds/ft3
  32°F/0°C	0.99987	62.416
  39.2°F/4.0°C	1.00000	62.424
  40°F/4.4°C	0.99999	62.423
  50°F/10°C	0.99975	62.408
  60°F/15.6°C	0.99907	62.366
  70°F/21°C	0.99802	62.300
  80°F/26.7°C	0.99669	62.217
  90°F/32.2°C	0.99510	62.118
  100°F/37.8°C	0.99318	61.998
  120°F/48.9°C	0.98870	61.719
  140°F/60°C	0.98338	61.386
  160°F/71.1°C	0.97729	61.006
  180°F/82.2°C	0.97056	60.586
  200°F/93.3°C	0.96333	60.135
  212°F/100°C	0.95865	59.843