lesson 4-water and latent heat

Question 1

what are the properties of solid water compared to liquid water?

Answer 1

-molecules move further
apart when water freezes
-so ice is less dense than
water (9%),which lets it
float on water
-And ice is lighter than the
same volume of water

Question 2

what does amphoteric mean?
+example of it

Answer 2

-both an acid and a base
-water

Question 3

what happens when water moves from a higher to lower ordered state?

Answer 3

-energy is taken in from the surrounding environment
-this energy weakens the individual hydrogen bonds in H2O molecules
-so the environment loses energy in the form of heat, and cools
-endothermic

Question 4

what happens when water moves from a lower to a higher ordered state?

Answer 4

-thermal energy is added to the bonds
-called a release of latent heat
-exothermic

Question 5

how does energy transfer between warm and cold objects?

Answer 5

from warm to cold

Question 6

what is environmental degradation?

Answer 6

-humans use groundwater
-so the water table drops underground
-causing plants and bushes with shorter roots to die due to lack of water for photosynthesis

Question 7

oceanic water
-roughly .% _____ (1L has 35g salt)
-freezing point of seawater ______ as salt concentration increases, usually _%
-__% of earth is covered in water ,but __% of it is salty

Answer 7

-roughly 3.5% salinity (1L has 35g salt)
-freezing point of seawater decreases as salt concentration increases, usually 2%
-72% of earth is covered in water ,but 97% of it is salty

Question 8

fresh water
-naturally occurs in…
-__% of fresh water is in lakes, only 2% in _____
-freezes at _*C
-salt water: fresh water = __:1

Answer 8

-naturally occurs in glaciers, ice caps, rivers etc
-87% of fresh water is in lakes, only 2% in rivers
-freezes at 0*C
-salt water: fresh water = 40:1

Question 9

how often does someone get sick in Africa from water diseases?

Answer 9

every 20 seconds

Question 10

-how much of the total water do oceans hold?
-what does the largest ocean hold?
what do glaciers hold of total water, and fresh water

Answer 10

96.5%
Atlantic-50%
glaciers-1.7% total
-68.7% fresh

Question 11

what is biological water?

Answer 11

Water at the surface of proteins and DNA, within tissues, cells, and cytoplasm