where did avogadro's number come from?
100023
The  Faraday constant divided by the Electron charge  =\n\n Avogadro's number
705744
It's a number - first invented by the arabs
750574
3.01E23 atoms of tin is about one-half mole (one mole is Avogadro's number -- 6.023E23 -- of anything).  So, which of the numbers you give is roughly one-half of the atomic weight of tin -- 118.69 grams/mole?
849802
Start with one molecule Cl2/. Atomic weight: Cl=35.5, Cl2 = 71.\n\nMultiply by 1molCl2/6.02x10^23molecules Cl2. The molecules Cl2 cancel, leaving mols Cl2. Multiply by 71gCl2/1molCl2. The molsCl2 cancel, leaving gCl2 in one molecule. The 6.02x10^23 is Avogadro's number. It may be good to express 71 as 7.1x10^2 in orderto use exponential notation throughout.
317381
History of Imaginary Numbers:\n\n\nComplex numbers were being used by mathematicians long before they were first properly defined, so it's difficult to trace the exact origin.\n \nThe first reference that I know of (but there may be earlier ones) is by Cardan in 1545, in the course of investigating roots of polynomials. During this period of time the notation underroot-1 was used, but more in the sense of a convenient fiction to categorize the properties of some polynomials, by describing how their roots would behave if we pretend that they have them. It was seen how the notation could lead to fallacies such as that described in the Classic Fallacies section of this web site, so square root -1 was considered a useful piece of notation when putting polynomials into categories, but was not seen as a real mathematical object. \n\nLater Euler in 1777 eliminated some of the problems by introducing the notation i and -i for the two different square roots of -1. With him originated the notation a + bi for complex numbers. He also began to explore the extension of functions like the exponential function to the case of complex-valued arguments. However, the numbers i and -i were called "imaginary" (an unfortunate choice of terminology which has remained to this day), because their existence was still not clearly understood. \n\nWessel in 1797 and Gauss in 1799 used the geometric interpretation of complex numbers as points in a plane, which made them somewhat more concrete and less mysterious. \n\nFinally, Hamilton in 1833 put complex numbers on a sound mathematical footing by showing that pairs of real numbers with an appropriately defined multiplication form a number system, and that Euler's previously mysterious "i" can simply be interpreted as one of these pairs of numbers. That was the point at which the modern formulation of complex numbers can be considered to have begun.
139780
Actually Ohm's law is recorded as I = V/R.  V is for volts.  I is used for current because, believe it or not all great scientists spoke english as their mother tongue.\n\nSome of the worlds most famous scientists also came from countries like France (Coulombe), Germany (Hertz), etc...\n\nI from current comes from the german word Intensität which means intensity.  It was a way of describing the change of charge (Q) with respect to time.
755325
The first thing we want to account for is that there are 6.02 x 10^23 molecules of H2O in one mole of H2O.  This is Avagadro's number, and it applies for the number of molecules in a mole, the number of atoms in a mole, etc.  So we want to see the problem up as follows:\n\nWe will start with our given quantity of molecules (2.48 x 10^26 molecules of H2O) and multiply this number by the ratio 1 mole of H2O/6.02 x 10^23 molecules H2O.  Essentially we are dividing 2.48 x 10^26 by 6.02 x 10^23.  The answer will be left with moles of H2O because the molecules of H2O will cancel each other, and we will be left with an answer.  \n\nFor a frame of referance, this answer is 4.12 x 10^2, or is it's not put into scientific notation, it is 412. molecules of H2O.
61490
The square root of 2, , also known as Pythagoras' constant, is the positive real number which, when multiplied by itself, gives the product 2. Its numerical value approximated to 65 decimal places (sequence A002193 in OEIS) is:\n\n1.41421 35623 73095 04880 16887 24209 69807 85696 71875 37694 80731 76679 73799. \n was the first known irrational number. Geometrically,  is the length of a diagonal across a square with sides of one unit of length; this follows from Pythagoras' theorem.\n\nA number called the silver ratio has the same expansion only starting with 2.4 rather than 1.4.
876756
Depends on what base was used.  Was it NaOH?\n\nOne mole of anything is 6.02 x 1023 (Avogadro's number) of that thing. One mole of an element is 6.02 x 1023 atoms of that element and is a mass of that element equal to its atomic weight in grams. One mole of a compound is 6.02 x 1023 molecules of that compound and equals its formula weight (the sum of the atomic weights of all the atoms in the formula) in grams. For example, 1 mole of C = 12 g C = 6.02 x 1023 atoms; 1 mole CO2 = 44 g CO2 = 6.02 x 1023 molecules of CO2. And (grams of compound) × (formula weight) = number of moles of compound (number of moles of compound) × (formula weight) = grams of compound.\n\n\nNa = 23\nO = 16\nH = 1\n1 mole of NaOH = 40 grams
910896
The answer comes from quantum mechanics and involves some graduate level math. \n\nThat being said the general rule is that a Principal quantum number can have up to 2n^2 electrons.
96063
It's AvOgadro :-)\nThe number is 6.0221415...x10exp23 (that is, followed by 23 zeroes).\nThis valuable number represents the number of atoms, molecules, etc. in a gram mole of any chemical substance.\nAvogadro (he had a really long name) proposed in 1811 that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules. More about this story in the second link.
5567
According to Wolfram Research, \n"An n-digit  number that is the sum of the nth powers of its digits  is called an n-narcissistic number. It is also sometimes known as an Armstrong number, perfect digital invariant (Madachy 1979), or plus perfect number.\n\nThe values obtained by summing the dth powers of the digits of a d-digit number n for n==1, 2, ... are 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 5, 10, 17, 26, ... (Sloane's A101337).\n\nThe smallest example other than the trivial 1-digit numbers is\n153==1^3+5^3+3^3.(1)\n\nThe first few are given by 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474, 54748, ... (Sloane's A005188). "
486246
I don't remember the atomic weight of Sodium offhand so I can't give you the exact answer but here's how to figure it out:\n\nDivide 10.4 by the atomic weight of Na (see the periodic table).  That will give you the number of moles of Na in 10.4 g.\n\nMultiply that number by Avogadro's number (6.023 x 10^23) to get the number of atoms.
569275
2 (to the power of) 30,402,457 - 1\n\nIt's ten million digits long....!!!  That's crazy.  It was only discovered last year too.\n\nBy the way, you can find out stuff like that so easily by googling
765367
The mole (symbol: mol) is the SI base unit that measures an amount of substance. One mole contains Avogadro's number (approximately 6.022×1023) entities. A mole is much like a dozen in that both units can describe any set of elementary objects, although the mole's use is usually limited to measurement of subatomic, atomic, and molecular structures, as a mole represents an exceedingly large number of entities.
957398
Atomic number\nThis was an idea by Mossely
1097097
For grams to mole, you find the molar mass of whatever substance you're working with (add the atomic masses together--it's the number with the decimal on the periodic table), and then put the number of grams you have of the substance over the molar mass.  That gives you the number of moles in the substance.\n\nFor moles to molecules, there are exactly 6.022 x 10^23 molecules of a substance per mole.  That's Avogadro's number.  Simply multiply the number of moles times Avogadro's number and you have the number of molecules.\n\nFor moles to ideal gases, there are 22.4 liters of an ideal gas at standard temperature and pressure per mole of gas.  Multiply your number of moles by 22.4 and you'll have how many liters.