Soc Sci Intro + Section 1: Physical Properties of Water (4-9)
What is the boiling point of hydrogen telluride?
-2.2℃
What is the boiling point of hydrogen selenide?
-42℃
What is the freezing point of hydrogen telluride?
-49℃
What is the boiling point of hydrogen sulfide?
-60℃
What is the freezing point of hydrogen selenide?
-64℃
What is the freezing point of hydrogen sulfide?
-84℃
What percentage of the reamining 3% is on the surface in lakes, rivers, and swamps?
0.30%
What is the freezing point of water?
0℃
What is the boiling point of water?
100℃
How long does it take for the average human to die without water?
3 days
What is the chemical formula for photosynthesis?
6CO₂ + 6H₂O + Solar Energy -> C₆H₁₂O₆ + 6O₂
What percentage of Earth's water is unfit for consumption due to salt content?
97%
Who studied the paradox of value in depth?
Adam Smith (c.1723-90)
What percentage of the human body is made of water?
about 60%
What percentage of jellyfish is made of water?
about 95%
What is the chemical formula for hydrogen selenide?
H₂Se
What is the chemical formula for hydrogen telluride?
H₂Te
What is the chemical formula for ammonia?
NH₃
Why is water's high heat of vaporization important?
energy lost when water converts from a liquid to gas allows for evaporative cooling to occur
What is the paradox of value?
ex. diamonds mainly made of carbon (v abundant) but we have more water on earth so diamonds are worth more
What happens if a human loses 15% of its water content?
fatal
What is the most promising water replacement?
formamide (CH₃NO)
What would happen if the surface temperature of Venus/Mars rose a few degrees?
geography and geochemistry would change only slightly
As water freezes, what structure does its molecules arrange themselves into?
hexagonal crystalline structure
What are anthropogenic factors?
human influenced activity
Where is the vast majority of the other 3% located?
ice caps or far underground
Which of water's state is denser (solid or liquid)?
liquid
Why is formamide good?
liquid at a wide range of temperatures
What does biophilic mean?
meaning the substances'' properties are such that life will appear wherever it exists in large quantities
What happens if a human loses 4% of its water content?
mental impairment
Water's oxygen atom has a slightly positive/negative charge.
negative
Why is the substance above not being used today?
no evidence that it exists anywhere naturally
What is methane? Describe its properties.
not polar, can dissolve many substances, condenses to liquid at 182 degrees below zero, likely little free energy to drive life processes
Why is water the only compound that occurs in all 3 physical states at temperatures found commonly on Earth?
only compound whose 3 states are located in close proximity
Cellular respiration converts sugar to energy in the presence of ________.
oxygen
What type of bond keeps the 2 hydrogen atoms attached to the oxygen atom?
polar covalent bonds
What is ammonia? Describe its properties.
polar molecule, fairly common across universe, but not in large quantities
Water has a high degree of ________.
polarity
What does every living cell on Earth possess that isolates the inside of the cell from the water around it?
polarized membrane
Water's hydrogen atoms have a slightly positive/negative charge.
positive
What is photosynthesis?
process where plants use energy from the sun and carbon dioxide from the air to create sugars and requires lots of water
How are the surface temperatures like in places with an abundance of water?
relatively stable
What is environmental history?
study of the relationship of the human and nonhuman worlds over time
What happened in the most recent ice age?
surface temps few degrees lower than present -> more water locked in glaciers -> lower sea levels -> humans and other animals could walk across shallow sea between Asia and N. America
Give an example of how water's transformation from a liquid to a gas causes evaporative cooling.
sweat evaporative from skin
How are the surface temperatures like in places where water is rare (deserts or savannahs)?
temperatures fluctuate dramatically
What is liquid water's molecular structure?
tetrahedral structure
What is the density relationship for most substances?
they become denser as they get colder (solid would sink below liquid)
Why is most of the water on the planet salty?
water tends to break apart substances it comes into contact with
What would happen if the hydrogen bonds in water were just a little weaker?
water would only be a liquid at sub-zero temperatures
What do recent studies show that can dissolve substances more effectively than water and might facilitate life processes in certain circumstances?
"supercritical carbon dioxide" or super-heated or super-pressurized CO₂
What is the chemical formula for methane?
CH₄
What is the chemical formula for water?
H₂O
What is the chemical formula for hydrogen sulfide?
H₂S
Who first noted the paradox of value?
Plato
What is the solution of water on Earth described as?
briny solution
Water's heat ________ and heat of ____________ are very high.
capacity, vaporization
What does the presence of water vapor in the air do?
captures heat and stores it in the atmosphere
