Showing posts with label Science. Show all posts

Monday, March 14, 2011

Bottled Water

cross posted @Homeschooling Notebook
from March 24, 2010

Monday, March 7, 2011

VIDEO HERE

Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about. But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!

Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about.

But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!

One popular move is the jump shot. But many players release the ball too soon and miss the basket.
“"One of the most important things that I found is that the ball really needs to be released right at the top of the jump,"” Fontanella said.
At that moment, the player isn't moving -- his velocity is zero. Releasing the ball at the top gives the player better control of the ball and making it more likely that he will make the shot. Another shot, the lay-up, can be an easy shot to make by hitting the backboard at just the right spot.
“"I found the sweet spot for a right-hand lay-up and the sweet spot for a left-hand lay-up,”" Fontanella said.
The secret is hitting the top corners of the square on the backboard; the angle of the ball is perfect and lands the shot almost every time.
“"A little bit of knowledge of physics helps you play the game better,”" Fontanella said.
The American Association of Physics Teachers contributed to the information contained in the TV portion of this report.

BACKGROUND: Good basketball players develop their skills through endless repetition, hard-wiring the brain with the correct sequence of muscle movements for optimal play (“kinesthetic memory”). However, knowing a little basic physics can still help you improve your game. You can learn why you should put a spin on the ball, get tips on improving your free throws, and discover the secret to Michael Jordan'’s seemingly longer “hang time.”

PUTTING A SPIN ON IT: Once the basketball leaves the shooter’'s hand, it travels in an unchanging parabolic path that can be calculated using Newton’'s laws of motion. But putting a backspin on the ball can help you make more free throws. When a spinning ball bounces, it bounces back in the direction of the spin. If the ball hits the backboard or back of the rim, it will be directed toward into the basket. That’'s because when the ball makes contact with the rim or backboard, the backspin causes a change in velocity opposite to the spin direction, making it more likely that the ball will drop into the net softly.

HANG TIME: Michael Jordan earned the nickname “Air Jordan” because of his seemingly longer “hang time” making jump shots in games, but this is an illusion. How high someone can jump depends on the force used to push on the floor when starting to jump, which in turn depends on the strength and power of the jumper’s leg muscles. The harder and more powerful the jump, the higher and longer the flight. In order to leap four feet into the air, the hang time would be 1.0 seconds. Jordan had a few tricks up his sleeve to make that hang time seem longer. When he dunked, he held onto the ball a bit longer than most players, and actually placed it in the basket on the way down. He also pulled his legs up as the jump progressed so it appeared that he was jumping higher. But it still all happened in less than one second.

Cross Posted @ Homeschooling Notebook (March 7, 2011)
Source: Science Daily.com
original article date: November 1, 2007

Wednesday, February 9, 2011

Atomic Structure

An updated version of this lesson is available at Visionlearning: Atomic Theory & Ions & Isotopes
CHAPTER 1
In the last lesson we learned that atoms were particles of elements, substances that could not be broken down further. In examining atomic structure though, we have to clarify this statement. An atom cannot be broken down further without changing the chemical nature of the substance.

• For example, if you have 1 ton, 1 gram or 1 atom of oxygen, all of these units have the same properties. We can break down the atom of oxygen into smaller particles, however, when we do the atom looses its chemical properties.

• Another example: if you have 100 watches, or one watch, they all behave like watches and tell time. You can dismantle one of the watches: take the back off, take the batteries out, peer inside and pull things out. However, now the watch no longer behaves like a watch. So what does an atom look like inside?
Atoms are made up of 3 types of particles electrons , protons and neutrons . These particles have different properties.
• Electrons are tiny, very light particles that have a negative electrical charge (-).
• Protons are much larger and heavier than electrons and have the opposite charge, protons have a positive charge.
• Neutrons are large and heavy like protons, however neutrons have no electrical charge. Each atom is made up of a combination of these particles. Let's look at one type of atom:

A neutron walked into a bar and
asked how much for a drink.
The bartender replied,
"for you, no charge." -Jaime - Internet Chemistry Jokes

The atom above, made up of one proton and one electron, is called hydrogen (the abbreviation for hydrogen is H).

The proton and electron stay together because just like two magnets, the opposite electrical charges attract each other.

What keeps the two from crashing into each other?

The particles in an atom are not still.
The electron is constantly spinning around the center of the atom (called the nucleus).
The centrifugal force of the spinning electron keeps the two particles from coming into contact with each other much as the earth's rotation keeps it from plunging into the sun.

Taking this into consideration, an atom of hydrogen would look like this:

A Hydrogen Atom

Keep in mind that atoms are extremely small. One hydrogen atom, for example, is approximately 5 x 10^-8 mm in diameter.

To put that in perspective, this dash - is approximately 1 mm in length, therefore it would take almost 20 million hydrogen atoms to make a line as long as the dash.

In the sub-atomic world, things often behave a bit strangely.
• First of all, the electron actually spins very far from the nucleus. If we were to draw the hydrogen atom above to scale, so that the proton were the size depicted above, the electron would actually be spinning approximately 0.5 km (or about a quarter of a mile) away from the nucleus. In other words, if the proton was the size depicted above, the whole atom would be about the size of Giants Stadium. • •Another peculiarity of this tiny world is the particles themselves.
Protons and neutrons behave like small particles, sort of like tiny billiard balls.
The electron however, has some of the properties of a wave.
In other words, the electron is more similar to a beam of light than it is to a billiard ball. Thus to represent it as a small particle spinning around a nucleus is slightly misleading. In actuality, the electron is a wave that surrounds the nucleus of an atom like a cloud. While this is difficult to imagine, the figure below may help you picture what this might look like:

Hydrogen: a proton surrounded by an electron cloud

While you should keep in mind that electrons actually form clouds around their nucleii, we will continue to represent the electron as a spinning particle to keep things simple!

In an electrically neutral atom, the positively charged protons are always balanced by an equal number of negatively charged electrons.

As we have seen, hydrogen is the simplest atom with only one proton and one electron.
Helium is the 2nd simplest atom. It has two protons in its nucleus and two electrons spinning around the nucleus. With helium though, we have to introduce another particle. Because the 2 protons in the nucleus have the same charge on them, they would tend to repel each other, and the nucleus would fall apart. To keep the nucleus from pushing apart, helium has two neutrons in its nucleus. Neutrons have no electrical charge on them and act as a sort of nuclear glue, holding the protons, and thus the nucleus, together.

A Helium Atom

As you can see, helium is larger than hydrogen. As you add electrons, protons and neutrons, the size of the atom increases. We can measure an atom's size in two ways: using the atomic number (Z) or using the atomic mass (A, also known as the mass number)

__________________________________________________________________________

CHAPTER 2
We can measure an atom's size in two ways: using the atomic number (Z) or using the atomic mass (A, also known as the mass number). The atomic number describes the number of protons in an atom. For hydrogen the atomic number, Z, is equal to 1. For helium Z = 2. Since the number of protons equals the number of electrons in the neutral atom, Z also tells you the number of electrons in the atom. The atomic mass tells you the number of protons plus neutrons in an atom. Therefore, the atomic mass, A, of hydrogen is 1. For helium A = 4.

Ions and Isotopes
So far we have only talked about electrically neutral atoms, atoms with no positive or negative charge on them. Atoms, however, can have electrical charges. Some atoms can either gain or lose electrons (the number of protons never changes in an atom). If an atom gains electrons, the atom becomes negatively charged. If the atom loses electrons, the atom becomes positively charged (because the number of positively charged protons will exceed the number of electrons). An atom that carries an electrical charge is called an ion. Listed below are three forms of hydrogen; 2 ions and the electrically neutral form.


H⁺ : a positively charged hydrogen ion	H : the hydrogen atom	H^- : a negatively charged hydrogen ion

Neither the number of protons nor neutrons changes in any of these ions, therefore both the atomic number and the atomic mass remain the same. While the number of protons for a given atom never changes, the number of neutrons can change. Two atoms with different numbers of neutrons are called isotopes. For example, an isotope of hydrogen exists in which the atom contains 1 neutron (commonly called deuterium). Since the atomic mass is the number of protons plus neutrons, two isotopes of an element will have different atomic masses (however the atomic number, Z, will remain the same).

Two isotopes of hydrogen


Hydrogen Atomic Mass = 1 Atomic Number = 1	Deuterium Atomic Mass = 2 Atomic Number = 1

If you would like to explore the interaction of protons and electrons further, the University of Colorado's Physics 2000 site has an interesting experiment posted on line. At the Electrical Force page, you can place an electron next to a proton and see how the electron moves. You can even try to build your own atom (and see how difficult it is)!

Cross posted @ http://homeschoolingnotebook.blogspot.com/2011/02/atomic-structure.html

SOURCES:
http://web.jjay.cuny.edu/~acarpi/NSC/3-atoms.htm
Natural Science Pages
Vision Learning

Tuesday, February 8, 2011

Atoms - WKRP in Cincinnati & Jefferson Lab & A is for Atom & Atom Song

All About Atoms
What are atoms?
Atoms are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms!
There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more.
Click here to continue

A is for Atom part1

A is for Atom part 2

The Atom Song

Cross posted @ http://homeschoolingnotebook.blogspot.com/2011/02/atoms-wkrp-in-cincinnati-jefferson-lab.html

Link Sources:
All About Atoms (Jefferson Lab)

Sunday, January 23, 2011

Non Newtonian Fluid

Note: I really HATE all the advertisements here but the info is good.

(fluid mechanics) A fluid whose flow behavior departs from that of a Newtonian fluid, so that the rate of shear is not proportional to the corresponding stress. Also known as non-Newtonian system.

Learn How to create a non-Newtonian fluid. For more Science How-To Videos & Articles, visit WonderHowTo.

CAVEAT!
1) I have no control over the lettering superimposed over this video.
2) Let me be clear ~~~> I do NOT recommend any other videos by this young man. -- I include this one only because it is harmless and it demonstrates a simple science experiment that introduces non-Newtonian properties that are easily experienced. AGAIN, I do NOT recommend any of his other videos.

THESE I DO RECOMMEND:
• Mythbusters Season 4 Disc 1
• AND!! Learn about the nature of fluids

FLUIDS IN GENERAL!

Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress. In everyday terms (and for fluids only), viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity. Put simply, the less viscous the fluid is, the greater its ease of movement (fluidity).^[1]
Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. For example, high-viscosity felsic magma will create a tall, steep stratovolcano, because it cannot flow far before it cools, while low-viscosity mafic lava will create a wide, shallow-sloped shield volcano. All real fluids (except superfluids) have some resistance to stress and therefore are viscous, but a fluid which has no resistance to shear stress is known as an ideal fluid or inviscid fluid.
The study of flowing matter is known as rheology, which includes viscosity and related concepts.

Cross posted @ http://homeschoolingnotebook.blogspot.com/2011/01/non-newtonian-fluid.html

SOURCES:
http://dsc.discovery.com/videos/time-warp-non-newtonian-fluid.html
http://www.answers.com/topic/non-newtonian-fluid
http://video.answers.com/learn-about-the-nature-of-fluids-83227076
http://www.youtube.com/watch?v=i_2u0fV3qTM&feature=channel

Saturday, January 22, 2011

Milk Fat Investigation

Cross posted @ http://homeschoolingnotebook.blogspot.com/2011/01/milk-fat-experiment.html
Note - Household Hacker is not a recommended source in most cases. This investigation is an exception.

Sunday, January 9, 2011

Science Quias

SCIENCE:
Chemistry - common elements:
http://www.quia.com/mc/65904.html

Atomic Structure: http://www.quia.com/rr/70834.html

30 Elements' Symbols (Matching Game)
http://www.quia.com/jg/907334.html

40 Elements' Symbols (Matching Game)
http://www.quia.com/jg/611032.html

Properties of Matter
http://www.quia.com/jg/611032.html

Periodic Table of Elements (Scavenger HUnt) check websites!
http://www.quia.com/sh/9629.html?AP_rand=642082197

Elemental Table (Rags to Riches)
http://www.quia.com/rr/41449.html

Atoms and Elements: http://www.quia.com/rr/41449.html

Cross posted @ http://homeschoolingnotebook.blogspot.com/2011/01/selected-quia-games-and-quizzes.html

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)

Happy Science Notebook