MYP Biology: Water & It’s Properties. Water is Essential to Life on Earth It is the ONLY substance...
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MYP Biology: Water & It’s Properties. Water is Essential to Life on Earth It is the ONLY substance on Earth that can be found naturally-occurring in all
Water is Essential to Life on Earth It is the ONLY substance on
Earth that can be found naturally-occurring in all states of matter
It makes up 60% of your body, 70% of your brain, and 80% of your
blood It covers more than 70% of the planet, but less than 3% of it
is drinkable
Slide 3
What is the Structure of a Water Molecule? HO 2 Hydrogen + 1
Oxygen These atoms are linked together by COVALENT bonds in which
they share electrons
Slide 4
What is the structure of a water molecule? Hydrogen Atoms
Covalent Bond Oxygen Atom
Slide 5
Water is a Polar Molecule A Polar molecule has positive and
negative poles due to unequal sharing of electrons in Covalent
bonds
Slide 6
Water is a Polar Molecule The larger atom(s) (Oxygen) pull more
of the electrons toward it and takes on a negative (-) partial
charge The smaller atom(s) (Hydrogen) have electrons pulled away
from them and take on a slight positive (+) partial charge
Slide 7
Water makes Hydrogen Bonds Hydrogen bonds are between the
oppositely charged ends of polar molecules (like water!)
Slide 8
Hydrogen Atom Oxygen Atom Covalent Bond Hydrogen Bond
Slide 9
Many Compounds Dissolve in Water Substances, like water, that
other compounds dissolve in are called SOLVENTS. The compounds
being dissolved in the solvent are called SOLUTES. Solutes and
solvents mix together to form a SOLUTION.
Slide 10
A Solution: Salt & Water SOLUTE (Salt) SOLVENT (Water)
Slide 11
Many Compounds Dissolve in Water Polar solvents dissolve POLAR
solutes Nonpolar solvents dissolve NONPOLAR solutes Polar &
Nonpolar do NOT mix
Slide 12
Some Compounds form ACIDS or BASES Acids release Hydrogen Ions
(H+) when they dissolve in water Bases remove Hydrogen Ions (H+)
when they dissolve in water
Slide 13
The pH Scale identifies how basic or acidic a solution is. The
scale runs from 0 to 14. Less than 7 = ACIDIC 7 = neutral Higher
than 7 = BASIC (Alkaline) Some Compounds form ACIDS or BASES
Slide 14
more acidic stomach acid pH between 1 and 3
Slide 15
bile pH between 8 and 9 more basic
Slide 16
Water has many special properties ADHESION & COHESION Water
molecules demonstrate ADHESION in their ability to stick to other
surfaces and COHESION in their ability to stick to each other. This
is due to the strong Hydrogen bonds they make.
Slide 17
Water has many special properties SURFACE TENSION The adhesive
and cohesive properties of water produce SURFACE TENSION, or the
ability of water molecules to form a thin surface skin.
Slide 18
Water has many special properties HIGH SPECIFIC HEAT Water
changes temperatures very SLOWLY. This is because it requires a
large amount of energy to disrupt waters strong network of Hydrogen
bonds.
Slide 19
Water has many special properties In most cases, the SOLID
state of matter is the most dense: But water is a special case
Slide 20
Water has many special properties SOLID Water is LESS Dense
than LIQUID Water Due to the geometry of the Hydrogen bonds between
water molecules, solid water (ice), is less DENSE than liquid
waterso it floats!
Slide 21
Water has many special properties UNIVERSAL SOLVENT Since it is
a POLAR molecule with neutral pH value, water is an excellent
solvent and is able to dissolve most compounds.
Slide 22
Waters properties make it essential to life Adhesion / Cohesion
Water flows through tubes/ vessels from roots to tree-tops which
allows plants to grow taller and transport water
Slide 23
Waters properties make it essential to life Surface Tension
Organisms can move across and live on top of bodies of water
Slide 24
Waters properties make it essential to life High Specific Heat
Stable environment for marine organisms Acts as effective coolant
(sweating) Helps maintain homeostasis in terms of organism body
temperature
Slide 25
Waters properties make it essential to life Ice is less dense
than liquid water (floats) Prevents water habitats from freezing
solid Preserves liquid water in colder temperatures Ice reflects
sunlight and regulates global temp.
Slide 26
Waters properties make it essential to life Universal Solvent
Dissolves and transports nutrients, gases, and waste through bodies
of organisms and habitats
Slide 27
pH = 3 Check for Understanding! Acid, Base, or Neutral? pH = 7
pH = 13
Slide 28
Hydrogen Atom Oxygen Atom Covalent Bond Hydrogen Bond Check for
Understanding!
Slide 29
Slide 30
Hot Water + Hot Chocolate Mix = Hot Chocolate Solvent = Water
Solute = Chocolate Mix Solution = Hot Chocolate