Thursday, November 25, 2010

Atomic Joke (no, really!)

Two atoms are walking down the street and they run into each other. One says to the other, "Are you all right?"

"No, I lost an electron!"

"Are you sure?"

"Yeah, I'm positive!"

___________________________________________________

What is an Atom?

Atoms make up all the matter around us including ourselves but what is an atom? The original definition of the word is ancient Greek and it was assigned to the theoretically smallest particle that could not be divided (atoma).
These days we know that atoms are made of yet smaller particles. There are three smaller particles that make up individual atoms. These are called subatomic particles as they are below the level of the atom in size.
The three particles are different in size and charge. Neutrons have no charge and are the largest subatomic particles. They are roughly the size of both a proton and an electron put together. Protons are slightly smaller than neutrons and have a positive (+) charge. Electrons are the smallest of all and carry a negative (-) charge.

The + and - charges are simply opposites of each other. They have been labeled + and - for convenience. Of course in reality these subatomic particles do not wear labels with their charge on them but it is easiest to the atom's structure if we keep the labels in place.It is also important to know that like charges repel and that opposite charges attract. This is best seen with two bar magnets. If you place the two North or South ends together they push apart whereas if you place a North and South end together they pull toward each other.
The protons and neutrons are clumped together in the middle of an atom and the electrons orbit around the outside. While this seems to contradict the idea that like charges repel, scientists have established that though protons (+) do indeed repel each other, once they are very close to each other another force, called the Strong Force, takes over and glues them together. The exact mechanism behind this force is not well understood.

What is an atom -- Electrons Orbiting
The electrons orbit the nucleus at great speed and distance. They are held in orbit by the pull of the oppositely charged protons in the nucleus and their speed prevents them from collapsing into the nucleus. This is similar to how satellites orbit the earth. As an example, for a Helium atom the structure is like this:

The electrons orbit the nucleus at such a great distance that 99.99% of the atom is empty space. The different numbers of protons and neutrons in the nucleus result in different elements and isotopes of those elements.

Cross posted @ http://homeschoolingnotebook.blogspot.com/2010/11/atomic-joke-no-really.html
SOURCES:
pun - Steve Schaffer (who else?)
http://www.green-planet-solar-energy.com/what-is-an-atom.html

Tuesday, November 23, 2010

Fun Math & Science Holidays

Square Root Day is an unofficial holiday celebrated on days when both the day of the month and the month are the square root of the last two digits of the year.For example, the last Square Root Day was March 3, 2009 (3/3/09), and the next Square Root Day will be April 4, 2016 (4/4/16). The final Square Root Day of the century will occur on September 9, 2081. Square Root Days fall upon the same nine dates each century.

Pi Day and Pi Approximation Day are two unofficial holidays held to celebrate the mathematical constant π (pi). Pi Day is celebrated on March 14, or in the month/day date format as 3/14; since 3, 1 and 4 are the three most significant digits of π. March 14 is also the birthday of Albert Einstein so the two events are sometimes celebrated together. Pi Approximation Day is held on July 22, or in the more common day/month date format as 22/7, which is an approximate value of π.

Mole Day is an unofficial holiday celebrated among chemists on October 23, between 6:02 AM and 6:02 PM,making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from Avogadro's number, which is approximately 6.02×10²³, defining the number of particles (atoms or molecules) in one mole of substance, one of the seven base SI units.
Mole Day originated in an article in The Science Teacher in the early 1980s. Inspired by this article, Maurice Oehler, now a retired high school chemistry teacher from Prairie du Chien, Wisconsin, founded the National Mole Day Foundation (NMDF) on May 15, 1991.
Many high schools around the United States, South Africa, Australia and in Canada celebrate Mole Day as a way to get their students interested in chemistry, with various activities often related to chemistry or moles.

Some schools celebrate Mole Day on June 2 (6/02 in MM-DD format) and occasionally February 6 (06/02 in DD-MM format), rather than October 23 (10/23), presumably from 10:23 AM to 10:23 PM.
Some schools celebrate "Mole Week" around October 23.
The American Chemical Society sponsors National Chemistry Week, which occurs from the Sunday through Saturday during October in which the 23rd falls. This makes Mole Day an integral part of National Chemistry Week.

& btw)

the square route of -1 = i

Cross Posted @ http://homeschoolingnotebook.blogspot.com/2010/11/fun-math-science-holidays.html

Monday, September 27, 2010

Periodic Table Fun

A cool photographic Periodic Table: http://periodictable.com/
A fun Quiz

Periodic Table of Elements

The periodic table is the most important reference a chemist has because it puts all the known elements into a meaningful pattern. Elements are arranged left to right and top to bottom in order of increasing atomic number. This order generally goes with increasing atomic mass.
Click on an element for more information (clicks take you to the Los Alamos National Laboratory site):

Period

1
IA
1A

18
VIIIA
8A

1
H
1.008

2
IIA
2A

13
IIIA
3A

14
IVA
4A

15
VA
5A

16
VIA
6A

17
VIIA
7A

2
He
4.003

3
Li
6.941

4
Be
9.012

5
B
10.81

6
C
12.01

7
N
14.01

8
O
16.00

9
F
19.00

10
Ne
20.18

11
Na
22.99

12
Mg
24.31

3
IIIB
3B

4
IVB
4B

5
VB
5B

6
VIB
6B

7
VIIB
7B

11
IB
1B

12
IIB
2B

13
Al
26.98

14
Si
28.09

15
P
30.97

16
S
32.07

17
Cl
35.45

18
Ar
39.95

–––- VIII –––-
–––- 8 –––-

19
K
39.10

20
Ca
40.08

21
Sc
44.96

22
Ti
47.88

23
V
50.94

24
Cr
52.00

25
Mn
54.94

26
Fe
55.85

27
Co
58.47

28
Ni
58.69

29
Cu
63.55

30
Zn
65.39

31
Ga
69.72

32
Ge
72.59

33
As
74.92

34
Se
78.96

35
Br
79.90

36
Kr
83.80

37
Rb
85.47

38
Sr
87.62

39
Y
88.91

40
Zr
91.22

41
Nb
92.91

42
Mo
95.94

43
Tc
(98)

44
Ru
101.1

45
Rh
102.9

46
Pd
106.4

47
Ag
107.9

48
Cd
112.4

49
In
114.8

50
Sn
118.7

51
Sb
121.8

52
Te
127.6

53
I
126.9

54
Xe
131.3

55
Cs
132.9

56
Ba
137.3

57
La*
138.9

72
Hf
178.5

73
Ta
180.9

74
W
183.9

75
Re
186.2

76
Os
190.2

77
Ir
190.2

78
Pt
195.1

79
Au
197.0

80
Hg
200.5

81
Tl
204.4

82
Pb
207.2

83
Bi
209.0

84
Po
(210)

85
At
(210)

86
Rn
(222)

87
Fr
(223)

88
Ra
(226)

89
Ac~
(227)

104
Rf
(257)

105
Db
(260)

106
Sg
(263)

107
Bh
(262)

108
Hs
(265)

109
Mt
(266)

110
Uun
()

111
Uuu
()

112
Uub
()

114
Uuq
()

116
- - -
()

118
- - -
()

Lanthanide Series

58
Ce
140.1

59
Pr
140.9

60
Nd
144.2

61
Pm
(147)

62
Sm
150.4

63
Eu
152.0

64
Gd
157.3

65
Tb
158.9

66
Dy
162.5

67
Ho
164.9

68
Er
167.3

69
Tm 168.9

70
Yb
173.0

71
Lu
175.0

Actinide Series

90
Th
232.0

91
Pa
(231)

92
U
(238)

93
Np
(237)

94
Pu
(242)

95
Am
(243)

96
Cm
(247)

97
Bk
(247)

98
Cf
(249)

99
Es
(254)

100
Fm
(253)

101
Md
(256)

102
No
(254)

103
Lr
(257)

The different rows of elements are called periods. The period number of an element signifies the highest energy level an electron in that element occupies (in the unexcited state). The number of elements in a period increases as one moves down the periodic table because as the energy level of the atom increases, the number of energy sub-levels per energy level increases.

In 1869, the Russian chemist Mendeleev noted that the repeating patterns of behavior could be arranged in a sequence of elements. This led to the first "Periodic Table" of the elements.
Scientists and students who are familiar with the periodic table use the position in the table to extract information about individual elements.
Chemistry in a Nutshell
For a list of the element names and symbols in alphabetical order.

Another way to explain it:

The periodic table arranges the chemical elements into a pattern so that you can predict the properties of elements based on where they are located on the table. Elements are arranged from left to right and from top to bottom in order of increasing atomic number or number of protons in the element.
Rows of elements are called periods. The period number of an element signifies the highest unexcited energy level for an electron in that element. The number of elements in a period increases as you move down the periodic table because there are more sublevels per level as the energy level of the atom increases.

Columns of elements help define element groups. Elements within a group share several common properties. http://chemistry.about.com/library/blperiodictablekids.htm

A more complex way to explain it:

The periodic table is a chart of the elements arranged according to

the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J.

Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled Periodic Table). The vertical columns, or groups, are numbered from I to VIII, with a final column numbered 0. Each group is divided into two categories, or families: one called the a series (the representative, or main group, elements); the other the b series (the transition, or subgroup, elements).

All the elements in a group have the same number of valence electrons and hence similar chemical properties.

The horizontal rows of the table are called periods. The elements of a period are characterized by the fact that they have the same number of electron shells; the number of electrons in these shells, which equals the element's atomic number, increases from left to right within each period.

In each period the lighter metals appear on the left, the heavier metals in the center, and the nonmetals on the right. Elements on the borderline between metals and nonmetals are called metalloids.Group Ia (with one valence electron) and group IIa (with two valence electrons) are called the alkali metals and the alkaline-earth metals, respectively.

Two series of elements branch off from group IIIb, which contains the transition elements, or transition metals; elements 57 to 71 are called the lanthanide series, or rare earths, and elements 89 to 103 are called the actinide series, or radioactive rare earths; a third group, the superactinide group (elements 122—153), is predicted to fall outside the main body of the table, but none of these has yet been synthesized or isolated.

The nonmetals in group VIIa (with seven valence electrons) are called the halogens.

The elements grouped in the final column have no valence electrons and are called the inert gases, or noble gases, because they react chemically only with extreme difficulty.

In a relatively simple type of periodic table, each position gives the name and chemical symbol for the element assigned to that position; its atomic number; its atomic weight (the weighted average of the masses of its stable isotopes, based on a scale in which carbon-12 has a mass of 12); and its electron configuration, i.e., the distribution of its electrons by shells.

The only exceptions are the positions of elements 103 through 116; complete information on these elements has not been compiled.

Larger and more complicated periodic tables may also include the following information for each element: atomic diameter or radius; common valence numbers or oxidation states; melting point; boiling point; density; specific heat; Young's modulus; the quantum states of its valence electrons; type of crystal form; stable and radioactive isotopes; and type of magnetism exhibited by the element (paramagnetism or diamagnetism).

See P. W. Atkins, The Periodic Kingdom: A Journey into the Land of Chemical Elements (1997).

Monday, September 20, 2010

Hurricane Resources (The Motherload)

Tuesday, September 14, 2010

Magic School Bus

A new Magic School Bus video! -- Climate Change
The video is EXTREMELY hokey at first but if you stick with it you will learn some great info!

Take a virtual field trip to Jersey City's Liberty Science Center!

Meet the author and illustrator, Joanna Cole (author) and Bruce Degen (artist).
~~> You will learn a little history about The Magic School Bus Series (began 25 years ago)
Cross posted @ http://homeschoolingnotebook.blogspot.com/2010/09/magic-school-bus.html

Sunday, September 12, 2010

Kate in Code

No. 2635
KATE IN CODE

by John H. Lienhard

Click here for audio of Episode 2635

Today, code for Kate. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.
The past gives up its secrets only by dribs and drabs. You've heard me talk about old Century Magazines. They give tantalizing hints about our forebears' thinking; but we must fill in the blanks.
Example: One Charles Barnard gives a mysterious title to his 1875 short story. It's just a line of horizontal bars: Long-short-long, short-long, long, short. I finally Googled Morse Code and, sure enough, they spell, Kate. The subtitle (written in words) says, An Electro-Mechanical Romance. Telegraphy was the great new technology of those times.
Kate, in code

Telephones would serve the next generation of Americans. But, for now, our lives were intertwined by telegraph lines. Most Americans would instantly have seen Barnard's title for what it was. Many would've understood what it said.

The story that follows is also odd. It's a literary piece that reads a bit like an extended technical manual. Barnard begins with the words, "She's a beauty." But his She is a locomotive, and he rhapsodizes: "A thing of grace and power, she seemed instinct with life as she paused upon her breathless flight."

Then we meet Kate. She's a telegraph operator at the railroad station. She comes out each day to wave at the locomotive's engineer, John. He sees her, then turns back to his engine. And Barnard's words now seem positively R-rated:

The steam-gauge trembles at 120^o, and quickly rises to 125^o. The vast engine trembles and throbs as it leaps forward.

Eventually, Kate teaches John to signal his coming by sounding her name in Morse Code on the train whistle. Each day, for a while, she hears that Morse tattoo, runs out to meet the train, climbs aboard -- and rides into the station with him.

But they fear their secret will be found out. So Kate contrives a new means for John to announce his arrival. She invents a trigger device by which the coming train can close a loop in a wire that she's strung out on the ground. It in turn will ring a bell in her office. This involves considerable inventive verve. She has to build her own battery using a pickle jar. But her system works.

Then, one evening the bell rings at the wrong time. John is headed for a collision and he doesn't know it. Kate finds a lantern, intercepts the train, and saves it. She and John are heroes and their story ends with this final flourish: "The winter's stars shone upon them, and the calm cold night seemed a paradise below."

Barnard was a prolific writer, pretty much forgotten today. He liked technology and he wrote engagingly. He reflected a world where new technologies of speed, power, and communication held our hearts. The past opens up to us for a moment when Barnard writes, "How perfect everything! ... From balanced throttle to air brake ... thirty-five tons of chained-up energy ... perfect expression of the highest mechanic art."

Cross Posted @ http://homeschoolingnotebook.blogspot.com/2010/09/kate-in-code.html
SOURCE: http://uh.edu/engines/epi2635.htm

Friday, July 16, 2010

Momentum and Marbles

MOMENTUM

Inertia means that a rolling ball on a smooth, level surface will roll forever if nothing stops it.

In fact, friction and air pushing against the moving ball will eventually bring it to a stop.

But interesting things happen when a motionless object gets in the way of a moving one. Try this and see for yourself.

Tape the yardsticks to a tabletop so they're parallel and about 1/2 inch apart.
Put 2 marbles in the middle of the sticks (our 'track') a few inches apart.
Flick a marble so that it rolls and hits the other one.

Notice that the one that had been rolling stops while the one that had been still now rolls!
The momentum of the rolling marble transfers to the other one, stopping the first and setting the second in motion.

Now put two marbles on the track so they touch, and a third several inches away.
Flick the single marble into the other two.

Notice that the rolling marble stops, the middle one stays put, and the third one rolls. The momentum went through the second marble into the third.

Try other combinations: two marbles into three still marbles, or three into three. You'll find that however many marbles you set in motion, the same number will be made to roll when they're hit.

This experiment introduces 3 concepts about and momentum :