Warm Up, October 24 th, )Why does water stick to itself? Why does water stick to most other things? 2)What do you think the term surface tension means (as it relates to water)? 3)Write the molecular formula for water and draw a water molecule. 4)Why is water special (other than it supports life) Pre-Assessment Water 2 Then Graphing old Pre and Post Water 1 GRAPHING SUCCESS (EXAMPLE) The Strange and Wonderful Mr. Water Water is an interesting, very unique, and required material in your every day life. But what makes water so great, you ask? 1.It DISSOLVES most stuffeventually UNIVERSAL SOLVENT The Strange and Wonderful Mr. Water 1.It DISSOLVES most stuffeventually UNIVERSAL SOLVENT 2.It occurs NATURALLY in ALL 3 STATES of matter. The Strange and Wonderful Mr. Water SOLID liquid gas 1.It DISSOLVES most stuffeventually UNIVERSAL SOLVENT 2.It occurs NATURALLY in ALL 3 STATES of matter. 3.Its NECESSARY for LIFE! The Strange and Wonderful Mr. Water Its NECESSARY for LIFE! The Strange and Wonderful Mr. Water 1.It DISSOLVES most stuffeventually UNIVERSAL SOLVENT 2.It occurs NATURALLY in ALL 3 STATES of matter. 3.Its NECESSARY for LIFE! 4.Its SOLID form (ice) is LESS DENSE than its LIQUID form. Why? Yeah I know that, but why? The Strange and Wonderful Mr. Water Short Chemistry Detour So heres a standard water molecule Whose molecular formula is H 2 O Short Chemistry Detour This same water molecule had a positive side and a negative side. And if you remember anything from 6 th or 7 th grade it should be magnets. So, like magnets, and the Earth; water has two poles. Short Chemistry Detour So based on that knowledge, how is water molecule 1 going to react to water molecule 2? Short Chemistry Detour The negative end is going to attract the positive end and vice versa. Because of this, we say water has polarity. THEY ACT LIKE TINY MAGNETS. Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. ADHESION COHESION Adhesion, from adhere, verb - meaning: stick fast to (a surface or substance). Cohesion, containing prefix co, - meaning: together or jointly Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. ADHESION COHESION Water will stick to other stuff and defy gravity. Water will also stick to itself! (polarity) Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. ADHESION Water will stick to other stuff and defy gravity. Example? Capillary action in plants! Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. COHESION Water will also stick to itself! (polarity) Think people cooperating! Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. COHESION Water will also stick to itself! (polarity) Also think, surface tension! Short Chemistry Detour Now, because water molecules act like tiny magnets, very unique situations occur. This random bug can balance on water, can you do the same with an ordinary staple? Do you even lift? Short Chemistry Detour So when water freezes, what happens and why does water expand???