Explain which group in the periodic table has the highest electronegativity values? Why do noble gases tend to have electro negativities of zero?
Halogens have the highest electronegativity values because as you move across to the right of the periodic table, the elements want to attract more electrons and protons to make the configuration more stable. Halogens have the largest, greatest desire to attract one more electron to become a noble gas stable configuration.
Green squares are the halogens http://www.bbc.co.uk/schools/gcsebitesize/science/images/38_modern_periodic_table.jpg
Noble gases tend to have electro negativities of zero because they have a stable configuration and do not want to attract electrons when their atoms are in a stable compound.
The Proton was discovered in 1918 by Ernest Rutherford when he sent alpha particles through nitrogen gas (7). It is not always clear who discovered the proton because the process of the discovery was slow and gradual, and many scientists contributed. Thomson and Chadwick helped, but Rutherford is credited with the discovery because he was the first to clearly prove the existence of protons (8).
Ernest Rutherford
originally from New Zealand, but moved to the UK to become a professor and teach future scientists (8)
won the Nobel Prize, was honored with knighthood, and overall became an icon (8)
because of the discovery of the proton he is referenced to as the "father of nuclear physics"(9)
What is a proton?
a nucleon (9) that produces a positive electrical charge (1)
composed of two "up" quarks and one "down" quark (1)
a quark is an elementary particle (2)
gluons hold quarks together (4)
a subatomic particle found in the nucleus of an atom (7)
a proton can be bounded by nuclear force and converted to atomic nuclei (9)
a proton without neutrons is usually a nucleus of a common hydrogen atom isotope (9)
The Experiment that proved the proton's existence:
Rutherford discovered the proton when he noticed the marks of hydrogen nuclei being released as the process of nitrogen was being converted into oxygen through a nuclear reaction involving the shooting of alpha particles into nitrogen gas (10)
Rutherford observed after shooting alpha particles into nitrogen gas that the scintillation (sparkle of light) detectors showed hydrogen nuclei indications that hydrogen could only have come from nitrogen (9)
(10)
Rutherford concluded nitrogen must be comprised of hydrogen nuclei
He named the hydrogen nucleus, with atomic number one, proton (9), which is "first" in Greek (3)
equation that explains nuclear reaction(10)
nuclear transmutation taking place (turning an element into another)(10)
Rutherford performed another experiment where he shot alpha particles(helium nuclei produced by radioactive decay) at gold foil because he was trying to prove the model of an atom (4)
unpredicted from what he thought, some of the alpha particles passed through the gold foil, and others bounced back (4)
Rutherford recognized from his experiment that the alpha particles bounced back because the atom was made of a dense nucleus surrounded by a cloud of orbiting electrons (4)
once the electron was discovered, Rutherford reasoned that there were positive charge centers within the atom to balance the negative electrons and create electrically neutral atoms (6)
Rutherford's discovery of the nucleus proves that the positive charges were concentrated in a very small fraction of the atom's volume (6)
Rutherford and other physicists compared the nuclear masses to charges and realized that the positive charge of any nucleus could be accounted for by an integer number of hydrogen nuclei (6)
Video for clearer explanation of the gold foil experiment(proved protons were positive charged particles) below
(11)
Importance that came from the discovery of the proton:
milestone in the development of atomic theory because it provided a greater understanding of how molecules bond and work (7)
Rutherford discovered he could change one element into another by striking it with energetic alpha particles, helium nuclei, where in each case the helium nuclei were released in the process (6)
number of protons in the nucleus of an atom determines which chemical element the atom is (7)
Fun Facts:
scientists believes a proton lives for at least 10^31 years (2)
the Large Hadron Collider(LHC) is the world's most powerful particle accelerator and can smash protons (5)
In 1920 protons first appeared in print(newspapers, magazines) (6)
Work Cited 1. http://www.physicsoftheuniverse.com/scientists_rutherford.html 2."Proton." Columbia Electronic Encyclopedia, 6th Edition (2009): 1. Vocational and Career Collection. EBSCO. Web. 30 Sept. 2010.
3."Chadwick Proves the Existence of the Neutron." 379. Salem Press/Magill Books, 1999. Science Reference Center. EBSCO. Web. 30 Sept. 2010.
4."Holey grail." Economist 367.8319 (2003): 72. MAS Ultra - School Edition. EBSCO. Web. 30 Sept. 2010.
5. Castelvecchi, Davide. "Bring it on!." New Scientist 193.2588 (2007): 36. Science Reference Center. EBSCO. Web. 30 Sept. 2010.
The object I chose was heavy whipping cream.
I chose this object beacause I was curious how it would react to other mixtures.
Physical Properties:
creamy white
liquid
homogeneous mixture
in each experiment I used 60 mL
low viscosity
odor is not strong but smells like milk
30 ML x 2 = 60 ML
flows fast
Chemical Properties (Experiments):
Mix in blender on speed 4 (medium speed) for 10 minutes
before mixed
after mixed
thickens into clumps, squishy, slimy
Chemical changes occurred when the composition changed to a solid and once the cream was mixed for a few minutes the mixture became a little warmer (exothermic reaction)
I performed this experiment because I hoped the cream would turn into a solid and maybe heat up, but it only became a little warmer (a little cooler than room temperature)
2. Add 30 ML of vinegar and stir.
thickened
I added vinegar to create a chemical change because I hoped it would change colors, since vinegar is an acid, but it did not.
A small chemical change occurred when the mixture thickened because the composition changed
left is before vinegar and right is with vinegar
3. Add 30 ML of lysol cleaner and stir.
after lysol was added
became a very thin liquid (lower viscosity than original)
became whiter with soap bubbles
I used Lysol because it is 3-4 % potassium hydroxide(http://en.wikipedia.org/wiki/Lysol) which is very exothermic in water (http://en.wikipedia.org/wiki/Potassium_hydroxide).
I hoped the chemical changes that would occur would be the transfer of heat (exothermic reaction) and a change in color because Lysol contains acid.
A chemical change did occur because the cream's composition changed into a thin bubbly mixture and the color changed to white rather than creamy white.
4. Add 30 ML of sink water and stir.
I added water because I hoped a new, more liquid like composition would be created and the color would change.
The chemical changes which occurred were the variation of a more white color and the mixture changing composition to a more liquid state.
It is possible the mixture could have reacted differently to distilled water because the sink water has chemicals in it
5. Add 20 ML of salt and stir
thickended immediately
salt absorbed cream and created clumps on the bottom
tastes salty
I picked salt because I hoped it would absorb in the heavy whipping cream and create a new composition.
The chemical properties were salty taste and the result of a new composition.
It is possible the mixture could have reacted differently if I used sodium instead of table salt because table salt has other elements mixed in it.
Conclusion:
I learned how butter is formed. By whipping and adding table salt the cream becomes the solid state of butter.
