2 Lesson: BIO.A.2.1. Water Properties

Water Properties

Water in the Human Body

• Water is an essential need in our body.

• Our body consist of 65% of Water

Water Structure

• H₂O

• Two hydrogen atoms with one oxygen atom.

• Held together by a Polar Covalent Bond (don't share evenly). So partial charges of positive and negative.

Water Partial Charges

• Polar Covalent Charge

• Electrons are not shared evenly

• Electrons are pulled toward the oxygen moe than hydrogen

• Important in reactions

Hydrogen Bond

• A weak bond

• Bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other

Cohesion

• Water loves to stick to water

Adhesion

• Water loves to stick to other stuff

• Opposites attract positive to negative

Surface Tension

• The cohesive forces between molecules

• Acting as if it has a stretched elastic membrane

• The intermolecular attractive forces creates the surface tension

• Result of Cohesion and Adhesion

Capillary Action

• Movement of water molecules along a surface (adhesion and cohesion)

• Capillary action bring water from the roots to the leaves.

High Specific Heat

• Water has a high specific heat and transparent, so it takes more energy to heat up than land does.

• Take more energy to heat up water then other solutions.

• This is good because our bodies are 65% water and we need to have consistency (homeostasis).

Universal Solvent

Water is capable of dissolving more substances thean any other liquid

Water Density

• As a liquid water has a high density

• As a sold (ice) was has less density, and bonds expands, so ice floats in water.

• When water floats it works like a insulant to organisms below.

• Cold water is heavier than warm water.

Multiple Choice

What are the bonds called between a slightly positive hydrogen in a polar molecule and a negatively charged atom?

• Hydrogen Bonds

• Water Bonds

• Covalent Bonds

• Bail Bonds

Multiple Choice

Why does ice float?

• water expands when it freezes, making ice less dense than water

• water compacts when it freezes, making ice more dense than water

• hydrogen bonds in water push the ice to the surface

• ice is afraid of water, and avoids it

Multiple Choice

What is the term for water's ability to defy gravity and climb up a tube?

• Capillary Action

• Specific Heat

• Universal Solvent

• Magic

Multiple Choice

Water sticks well to many materials. What term relates to this property of water?

• cohesion

• adhesion

• density

• surface tension

Multiple Choice

Water is polar. What does that mean?

• it is a molecule with opposite charges on opposite ends

• it is a molecule with no charge

• it is a molecule with identical charges on opposite ends

• it is a molecule with too many protons

Multiple Choice

You body sweats to help prevent you from overheating. How does water regulate temperature?

• it lets heat pass through it

• it absorbs a lot of heat, then decreases in temperature

• it absorbs a lot of heat, but only increases a little in temperature

• heat is afraid of water and avoids it

Multiple Choice

Which of the following is the CORRECT list of water's properties?

Read Carefully!

• adhesion, cohesion, high specific heat, universal solvent

• adhesion, cohesion, low specific heat, universal solvent

• adhesion, no cohesion, low specific heat, universal solute

• no adhesion, cohesion, high specific heat, universal solute

Multiple Choice

Which of the following is an example of COHESION?

• water sticking to water

• water sticking to glass

• oil sticking to plastic

• hydrogen sticking to oxygen

Multiple Choice

What is the correct chemical formula for water?

• H₂O

• HO₂

• H₂O₂

• ₂H₁O

Multiple Choice

Which of the following can water NOT dissolve?

• Ionic Compounds

• Polar Compounds

• Nonpolar Compounds

Multiple Choice

Which of the following can water NOT dissolve?

• Salt

• Sugar

• Oil

• Baking Soda

Multiple Choice

Which part of a water molecule has a Negative Charge?

• The Hydrogen

• The Oxygen

• The Left

• The Right

Multiple Choice

Which part of a water molecule has a Positive Charge?

• The Hydrogen

• The Oxygen

• The Top

• The Bottom

Multiple Choice

What kind of molecule is water?

• Ionic

• Polar Covalent

• Nonpolar Covalent

• Metallic