What does atomic number represent?
365377
atomic number represents the number of protons or electrons in an atom
291470
Yes, you are correct. The atomic number of Molybdenum is 42.
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1.ATOMIC NUMBER\n2.ELECTRON\n3.SHELL\n4.ORBIT
829932
Take radium and subtract two from its atomic number. Then find the element with that result as its atomic number. I'm too lazy to see what that is right now.
844991
Potassium is number 19. That means it has 19 protons. If it is an atom and not an ion, it has the same nimber of electrons as protons. Since protons are positive + and electrons are negative - , they have to balance. You find the neutrons by subtracting the atomic number from the atomic mass, since both the protons and neutrons weigh 1 and make up the mass. The electrons in the energy levels can move to another atom in compound formation.(ions)
73226
Protons is the atom's atomic number.  It gives the atom its certain "chemical properties".  The proton has a weight of 1.  The neutron is a combination of a proton and electron roughly as evidenced by storing a neutron for more then 15 min and it will turn into a hydrogen atom.  For all intensive purposes the electron has no weight.  The neutron weighs 1 as well. When you combine the numbers of protons and neutrons in an atom you get the weight.  The neutrons act as glue for the atom and help keep it together.  Thus Uranium 235 is more unstable then Uranium 238. (235 is what they use in reactors).  The electron is attracted to the proton. Electron(-) proton (+).  But as you get towards the left section of the table you have atoms that want to lose their electrons since the want full orbitals.  As you get toward the right side of the table you get atoms that want to gain electrons to fill their shells.  These atoms that have a positive charge are known as cations longer word = positive. Shorter word or Ion = negative.
230287
The above answer is correct - but just knowing the atomic number of something will only definitively tell you the number of protons. The number of neutrons does not always have to match (and often does not).\n\nFor example, an atom with atomic number 9 has 9 protons (we know that much from the atomic number), but it has 10 neutrons. We get the second number from the atomic weight.
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The atomic number tells you how many protons there are in the nucleus, and that's what identifies the element.  Subtract that number from the atomic weight and you get the number of neutrons.  Uranium has 92 protons and 143 neutrons (U235) or 146 neutrons (U238).  The different weights are called isotopes.  In an electrically neutral atom the number of electrons is the same as the number of protons.  Strip a few electrons away you get an ion (an ionized atom).  It's the structure of the electrons that strongly influences the chemical properties of the element.
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Francium has 87 protons.  This information is available on the Periodic Table of Elements, the atomic number (Z) of an element is the number of protons.
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Periodic Table is in order of increasing atomic no. so\n\n1st Step: find the placement of the element, in the present case it is on third place so no. of protons is three.\n\n2nd Step: In the Periodic Table, number of electron is always equal to number of protons so far three protons of Lithium there will be three electrons.\n\n3rd Step: Periodic Table also give atomic weights of the elements. Simply atomic weight is equal to sum of number of protons and nutroms.\n\n4th Step: Note the atomic weight of the element. Most of the elements in Periodic Table show atomic weights in fractions. In the case of Lithium it is 6.9 \n\n5th Step: Convert the fractional figure into nearest whole number. In case of Lithium it is 7\nNote:In the Periodic Table atomic weight is average of all isotopes (different atomic weights of same element). The nearest whole number refers to the most abundent  or the common atom (Isotop).\n\n6th Step: Subtract atomic number (protons) from atomic weight (neutron=proton), the difference is number of neutrons. In Lithium 7-3=4 so there are 4 neutrons
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n = 1,2,.....\n l = 0, 1, 2..... n-1\nm = -l, -(l-1)\n\nThe labels  are called quantum numbers, and made their debut in Sommerfeld's elliptical orbit model. They correspond to certain classical features of the orbit: \n\nn= sr. root of (semi major axis)\nl = orbital angular momentum\nm = orientation of the orbit
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Look up the atomic mass (sometimes called atomic weight) on the periodic table, and subtract the atomic number from it.  The atomic mass is (practically) equal to the total number of protons and neutrons, and the atomic number is equal to the number of protons.  When you subtract atomic number from atomic mass your subtracting the number of protons from the total number of protons and neutrons, which leaves you with just neutrons.
970267
it describes the # of protons & electrons in that element.
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chemistry if you're concerned with what element it is (which is determined by atomic number), or physics if you're concerned about nuclear reactions (which can potentially change the atomic number of an atom).
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The atomic number is the number of protons.
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The atomic number of Aluminum is 13 (look at a periodic table). This means 13 protons and 13 electrons (since these are oppositely charged they have to balance each other.) To find the number of neutrons you subtract the number of protons from the atomic mass (the atomic mass is 27). So 27-13= 14 neutrons
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Avagodro's number\n\nAvogadro's number and the mole are very important to the understanding of atomic structure. The Mole is like a dozen. You can have a dozen guitars, a dozen roosters, or a dozen rocks. If you have 12 of anything then you would have what we call a dozen. The concept of the mole is just like the concept of a dozen. You can have a mole of anything. The number associated with a mole is Avogadro's number. Avogadro's number is 602,000,000,000,000,000,000,000 (6.02 x 1023). A mole of marbles would spread over the surface of the earth, and produce a layer about 50 miles thick. A mole of sand, spread over the United States, would produce a layer 3 inches deep. A mole of dollars could not be spent at the rate of a billion dollars a day over a trillion years. This shows you just how big a mole is. This number is so large that it is usually only represented in scientific notation.\n\nProbably the only thing you will ever have a mole of is atoms or molecules. One mole of magnesium atoms (6.02 x 1023 magnesium atoms) weigh 24.3 grams. 6.02 x 1023 carbon atoms weigh a total of 12.0 grams. 6.02 x 1023 molecules of CO2 gas only weigh a total of 44.0 grams. The decimal number on the periodic table is the atomic mass, the mass of one atom measured in atomic mass units(amu). Amu's are defined to be 1/12 the weight of the most common isotope of Carbon. This number in grams is the mass of 1 mole of that element. For example, 6.02 x 1023 iron atoms weigh only 55.847 grams.(This is equivalent to saying one mole of iron atoms weighs 55.847 grams.) One mole of sulfur weighs 32.066 grams. (This is the same as saying 6.02 x 1023 Sulfur atoms weigh 32.066 grams)\n\nWhen not measured in grams, the decimal number on the periodic table is called the atomic mass and is in atomic mass units(amu). As mentioned earlier, one proton weighs 1.0073 amu and 1 neutron weighs 1.0087 amu. So the atomic mass is the mass in amus of one atom of an element, but you rarely use the mass of one atom. Even if you have a tiny speck of a metal or a microgram of an element, you have billions and billions of atoms. Thus, the mass in grams of one mole of an element (the gram atomic weight) is more useful.