recycled -- verne rockcastle

verne rockcastle - TST --- 1979 (?)

In the 'fillosophee folder' is another article verne wrote -- lazy student

the glass of water you're about to drink deserves
a second thought, i think.
for Avogadro, oceans, and those you follow
are all involved in every swallow.
the molecules of water in a single glass
in number, at least five times, outclass
the glasses of water in stream and sea,
or wherever else that water can be.
the water in you is between and betwixt,
and having traversed is thoroughly mixed.
so someone quenching a future thirst
could easily drink what you drank first !
the water you are about to taste
no doubt represents a bit of the waste
from prehistoric beast and bird ...
a notion you may find absurd.
the fountain spraying in the park
could well spout bits of Joan of Arc,
or Adam, Eve, and all their kin
you'd be surprised where you drink has been !
just think ! the water you cannot retain
will some day hence return as rain,
or be beheld as the purest dew,
though long ago it passed through you !

recycled

here is an opportunity to relate Avogadro's number to a glass of water and to the recycling of water in a way that appeals to generate thoughtful consideration. Give each student a glass or cup of water, and as they drink . . .

(1) ask them to sip without letting their upper lip touch the water. It is almost impossible for most people to do this. In ordinary sipping or drinking, the upper lip contacts the water, and the tongue is depressed inside the mouth. Because of the partial vacuum formed, atmospheric pressure forces water into the buccal cavity. From there, the water can be swallowed.

(2) write Avogadro's number on the board. You may want to describe how the number was determined, or have the class do some digging on their own to find out. Explain that 6.02 x l0 to the 23 is a number of molecules of a substance in one mole or gram molecular mass of the substance. For example,

one gram molecular mass of water is l8 g on the Periodic Chart, Hydrogen = 1 and Oxygen =16, so H20 = 18

Show the class ( 18 ml ) of water -- ( 1/2 oz ) the amount containing Avogadrošs # of molecules.

By comparison, a glass with 200 g of water has 11 times as much water as 18 g -- therefore it has 11 times 6.02 x l0 to the 23 molecules.

This is = 6.6 x 10 to the 24 molecules

all the water on earth ( oceans, lakes, rivers, ground water atmosphere, glaciers and organism ) equals about ( 1.4 x 10 to the 24 g )

So, a single glass of water has about 5x a many molecules as there would be glasses of water in all the earth.

6.6 x 10 to the 24 ~ 5 times 1.4 x l0 to the 24 g molecules in one glass ---------- glasses in the ocean

the unedited article

on several occasions I have had the opportunity to relate Avogadro's number to a glass of water and to the recycling of water in a way that appeals to generate thoughtful consideration. Students enjoy the exercise and are likely to share it with others, probably at the dinner table that night. Try it in your class. Give each student a glass or cup of water. As they drink, point out at least two things.

first, ask the students to sip without letting their upper lip touch the water. It is difficult, if not impossible, for most people to do this. In ordinary sipping or drinking, you explain the upper lip contacts the water, and the tongue is depressed inside the mouth. Because of the partial vacuum formed, atmospheric pressure forces water into the buccal cavity. From there, the water can be swallowed.

in the beginning, have the class concentration on the mechanics of drinking, This will ensure that they drink the water before you read the second part of the exercise.

write Avogadro's number on the board. You may want to describe how the number was determined, or have the class do some digging on their own to find out. In any case, explain that this number, 6.02 x l0 to the 23rd is a number of molecules of a substance in one mole or gram molecular mass of the substance.

For example, one gram molecular mass of water is l8g.
Pour this mass of water in a graduate cylinder ( 18 ml ) and show the class just what mass of water contains Avogadros number of molecules. By comparison, a glass with 200g of water has 6.6 x l0 to the 24th molecules ( about 10 x as many: 18 g vs 200g ).

all the water on earth in the oceans, lakes, rivers, ground water atmosphere, glaciers and organism, equals about l.4 x l0 to the 9th cu km --
1,400,000,000 cubic kilometers
or it could be stated as l.4 x l0 to the 24 ml
1,400,000,000,000,000,000,000,000 cubic cm or ml

and has a mass about l.4 x l0 to the 24th g.

This means that in a single glass of water there are about 5x a many molecules as there would be glasses of water in all the earth.

the molecules in a glass of water have been recycled many times. The period for recycling is long; about 3000 years on the average for sea water and up to l0,000 years for deep ground water.

in the following verses, I have taken some license for rhyming and for compressing the time scale. You might read this poem to your students to enrich their understanding of recycling as they bravely finish their drinks of water.