Studied by 8 people
what is oxygens atomic number
8
what is hydrogens atomic number
1
how many oxygens and how many hydrogens are in a water molecule
1 oxygen and 2 hydrogens
how many valence electrons does oxygen have
6 valence
how many valence electrons does hydrogen have
1 valence
what kind of bond is formed between the oxygen and the hydrogen in a water molecule
covalent bonds
what does covalent mean
the two atoms share electrons (only their valence electrons)
how many bonds are needed to give oxygen an outershell
2 bonds
how many bonds is needed to give hydrogen a full outer shell
1 hydrogen bond is needed
what does it mean when oxygen has a high electronegativitiy
it means the oxygen atom has a big affinity for the electrons in a covalent bond (its an electron hog)
what is meant when it says water molecules are polar
there is a slight negative charge on one side and a slight positive charge on the other side
why do the electrons tend to hang around the oxygen atom in a water molecule
oxygen has a high electronegativity
what happens as a result of the electrons all hanging out near the oxygen
there is now a negative charge on the oxygen side and a positive charge on the hydrogen side due to the imbalance of electrons
what does waters polarity allow it to do?
form weak bonds with other water molecules
what are the weak bonds called that are formed between water molecules?
hydrogen bonds
hydrogen bonding of water is crucial to what?
life on earth
what is the symbol for a partial charge
δ
what is the seperation of charges called
polarity
what does polar covalent mean
the uneven sharing of electrons resulting in a seperation of charges in a molecule
what does cohesion mean
when two of the same molecules form a hydrogen bond
what is an example of cohesion
water forming hydrogen bonds with other water molecules
what is adhesion
when different polar molecules form hydrogen bonds
what is surface tension
it is a result of the cohesion of water molecules at the surface of water
what is surface tension kind of like?
a weak barrier between the air and the water
whats an example of surface tension
paper clip floating on water
what is capillary action
the ability of water to climb small tubes against gravity
what causes capillary action
adhesion
capillary action is caused by the _________ of water to the side of the tube and by _____________ to itself.
adhesion, cohesion
what is an example of cohesion
trees moving water through capillary action
what is specific heat
the amount of energy needed to raise the temperature of a substance by 1 degree celcius
what is heat of vaporization
the energy needed to convert liquid to a gas (to vaporize the liquid)
water has a high _____________
specific heat
how does water and earths temperature relate
the oceans help to regulate earths temperature d
water also helps to do what to our bodies
regulate our temperature
why do desert’s temperatures constantly fluctuating
deserts do not have water to help regulate temperature
what is evaorative cooling
when water absorbs and dissipates heat as it evaporates
when it is humid out, why cant the water from our skin evaporate?
because there is already water in the air
why can water dissolve polar and ionic molecules
the water molecules attatch to the molecules and pull them apart and surrounds the individual molecules
what is it called when a substance is dissolved in water and the water molecules fully surround the atoms
hydration sphere
fats and oils are _______________
hydrophobic (hate water)
what is the density anomaly
when ice is less dense than water
why is ice less dense than water
as the water cools down, the molecules slow down and begin to slightly repel each other, which allows for air to get trapped which makes it less dense
why is floating ice important for life in aquatic ecosystems
floating ice allows for the ice to thaw, preventing the freezing of entire bodies of water
why can life continue in freezing bodies of water q
ice acts as an insulating top layer, which regulates temp of water underneath the ice
Note 
Flashcard (41)