Question

describe the following properties of water:
Density:
Surface Tension

Answer 1

The density of water is the weight of the water per its unit volume, which depends on the temperature of the water. The density of pure water actually is somewhat less than 1 g/cm3. Here's a table listing the values for the density of liquid water. Note that water can be supercooled where it remains liquid well below its normal freezing point. The maximum density of water occurs around 4 degrees Celsius. Ice is less dense than liquid water, so it floats.
Water also has a high level of surface tension. This means that the molecules on the surface of the water are not surrounded by similar molecules on all sides, so they're being pulled only by cohesion from other molecules deep inside. These molecules cohere to each other strongly but adhere to the other medium weakly.