The science of how Messi keeps the ball close to himself photo credit: ZaleDesigns Messi is a magician with the ball at his feet. He's in my opinion the best player in the sense that he can control the ball so well, runs so fast with the ball & changes the direction at full speed like it's a walk in the park. For starters he started playing very early (at 3) which is crucial if you want to be a good player. In that aspect, he's God gifted as he had dribble skills which is genetic in my opinion. Height He is short which means a low center of gravity so it's difficult to push him off the ball. That's why we see that anyone rarely can topple him down, instead players much larger than him lose possession to him. So his short height suits his style of play & is a blessing in disguise. Change of pace Messi changes his pace really well. He starts slow and runs directly at the defender which means the defender has to stop & focus on him. When he reac...
Chemistry - Gold
Introduction
Gold is a bright, reddish yellow, soft, dense, malleable, and ductile metal naturally found in the earth’s crust.
The symbol of gold is ‘Au’ and atomic number is ‘79.’
Gold is (chemically) a transition metal and belongs to group 11 of the periodic table.
Salient Features of Gold
Gold, which remains in a solid state under standard conditions, is the least reactive element.
Gold is resistant to most of the acids.
Gold does dissolve in aqua regia; aqua regia is a mixture of nitric acid and hydrochloric acid.
However, gold is insoluble in nitric acid.
Gold usually dissolves in alkaline solutions of cyanide.
Cyanide solutions are commonly used in mining and electroplating.
Gold also dissolves in mercury and forms ‘amalgam alloys.’
Gold does not react with oxygen at any temperature.
Occurrence of Gold
Gold commonly occurs as a free element i.e. in the natural form.
Gold occurs as nuggets or else found in in rocks, grains, in veins, and in some other alluvial deposits.
Gold also occurs in a solid solution forms with the native element such as silver (as electrum).
At some places, gold also naturally alloyed with copper and palladium.
Alloys of Gold
Following are the major alloys of gold −
Colored gold
Crown gold
Electrum
Rose gold
Tumbaga
White gold
Compounds of Gold
Following are the major compounds of the gold −
Gold (III) chloride -AuCl3
Gold (I) chloride - AuCl
Cyanide - CN
Chloroauric acid -HAuCl4
Gold (III) oxide -Au2O3
Gold bromide - AuBr
Aqua regia -HNO3+3HCl
Gold bromide - AuBr3
Gold (III) hydroxide -AuH3O3
Gold fluoride - AuF3
Gold (V) fluoride -AuF5
Gold sulfide - Au2S
Fulminating gold
Gold salts
Gold heptafluoride
Uses of Gold
Gold is one of the oldest elements that human being have been using for thousands of years.
As it is highly precious and provides a beautiful look, hence it is characteristically used in making ornaments.
As per the recent trend (of the world), about 50% gold is used in making jewelry, 40% used in investments, and remaining 10% is used in industry.
So this is why gold is so expensive right?
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