29 August 2012

LHP 20: Water Acrostic RHP 21: Water Molecule

Water

The Water Molecule

• H2O

• Water is a polar molecule– It has a positive and a

negative end.– Overall neutral charge

Polar Molecules

• Electrons are pulled closer to larger nucleus.

Hydrogen Bonds

• Attraction of partial opposite charges between hydrogen and oxygen [for example]

• Polar molecules attract to other polar molecules .

Water’s polarity allows it to dissolve sodium chloride [NaCl] and many other ionic and polar compounds.

Cohesion

• Attraction between molecules of the same substance.– Ex. Water beading up on smooth surface.– Try floating a metal pin on water.

Adhesion

• Attraction between molecules of different substances.– Capillary action

Water

• Water expands when it freezes. So ice is less dense than liquid water and it floats.

IAN LHP

• Draw a water molecule – Illustrate its polarity

• Water Acrostic– 5 sentences about water’s properties.

WATER

Water is essential to all life. Clean drinking water is vital to human health.

In many developing countries women and children spend many hours simply collecting water.

What would you do?

• How would you go about solving this problem?