How many quantum numbers are used to describe the energy state of an electron in an atom?
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Four.\n\nThe first one is usually called "n" and it gives what people think of when they say "energy level".  It's also called the "principal quantum number", I think.\n\nThe next one is usually called "l" (el) and for a given energy level, it can be anything from 0 up to "n-1".  These correspond to what people sometimes call "shells", such as the s, p, d, f, etc. shell.\n\nThe next one is called "m" and is sometimes called the "sub-shell".  Each shell can have up to "2*l+1" sub-shells.  So an "s shell" (l=0) can have 1 sub-shell.  A "p shell" (l=1) can have 2*1+1=3 sub-shells, etc.\n\nThe final quantum number is called "s" or "spin".  For each sub-shell, this can take on one of two values, +1/2 or -1/2  in some books.  This means that only two electrons are allowed in any given sub-shell.\n\nSo for n=1, the only option is l = 0, which means further that m must be 1, with 2 choices for s.  This all means that the first energy level can only hold 2 electrons.\n\nFor n=2, l can be either 0 or 1.  For l =0, m must again be 1, allowing 2 electrons.  For l = 1, m can be as much as 3, each allowed to have 2 electrons.  So adding the 2 electrons for the l=0 subshell to the 6 allowed in the 3 possible subshells for l=1 (6 electrons we get a total of 8 electrons allowed in the second energy level.\n\nYou can continue on to get totals of 18 (2 + 6 + 10) for the 3rd energy level (n=3; l =0, 1, or 2;  and m = 1, 3 and 5, each with 2 electrons allowed).\n\nThis is where the numbers that correspond to "filled energy levels" come from in the periodic table.
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True.\nThe electron in an hydrogen atom can only have certain energies. Which energy levels are allowed can be explained by quantum mechanics. Everytime an electron jumps from one level to a lowel one it gives of a photon of light with a frequency corresponding to the difference in energy of the two level. Therefore only certain frequencies are allowed.
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ATOM..basic building block\n \n[Gr.,=uncuttable (indivisible)], basic unit of matter; more properly, the smallest unit of a chemical element having the properties of that element.  That is the definition.  Continue to read further; it really gives great detail!!!!!\n\nStructure of the Atom\n\nThe atom consists of a central, positively charged core, the nucleus, and negatively charged particles called electrons that are found in orbits around the nucleus.\n\nThe Nucleus\n\nAlmost the entire mass of the atom is concentrated in the nucleus, which occupies only a tiny fraction of the atom's volume. The nucleus of an atom consists of neutrons and protons, the neutron being an uncharged particle and the proton a positively charged one. Their masses are almost equal. Atoms containing the same number of protons but different numbers of neutrons represent different forms, or isotopes, of the same element.\n\nThe Electrons\n\nSurrounding the nucleus of an atom are its electrons; for a neutral atom, the number of electrons is equal to the atomic number. The outermost electrons of an atom determine its chemical and electrical properties. An atom may combine chemically with another atom in various ways, either by giving up or receiving electrons, thus setting up an electrical attraction between the atoms (see ion), or by sharing one or more pairs of electrons (see chemical bond). Because metals have few outermost electrons and tend to give them up easily, they are good conductors of electricity or heat (see conduction).\n\nThe electrons are often described as revolving about the nucleus as the planets revolve about the sun. This picture, however, is misleading. The quantum theory has shown that all particles in motion also have certain wave properties. For a particle the size of an electron, these properties are of considerable importance. As a result the electrons in an atom cannot be pictured as localized in space, but rather should be viewed as smeared out over the entire orbit so that they form a cloud of charge. The electron clouds around the nucleus represent regions in which the electrons are most likely to be found. The shapes of these clouds can be very complex, in marked contrast to the simple elliptical orbits of planets. Surprisingly, the sizes of all atoms are comparable, in spite of the large differences in the number of electrons they contain.\n\nAtomic Weight and Number\n\nThe atomic number of an atom is simply the number of protons in its nucleus. The atomic weight of an atom is given in most cases by the mass number of the atom, equal to the total number of protons and neutrons combined. An atom may be conveniently symbolized by its chemical symbol with the atomic number and mass number written as subscript and superscript, respectively. For example, the symbol for uranium is U (atomic number 92); the isotopes of uranium with atomic weights 235 and 238 are indicated by 23592U and 23892U.\n\nDevelopment of Atomic Theory\n\nEarly Atomic Theory\n\nThe atomic theory, which holds that matter is composed of tiny, indivisible particles in constant motion, was proposed in the 5th cent. by the Greek philosophers Leucippus and Democritus and was adopted by the Roman Lucretius. However, Aristotle did not accept the theory, and it was ignored for many centuries. Interest in the atomic theory was revived during the 18th cent. following work on the nature and behavior of gases (see gas laws).\n\nFrom Dalton to the Periodic Table\n\nModern atomic theory begins with the work of John Dalton, published in 1808. He held that all the atoms of an element are of exactly the same size and weight (see atomic weight) and are in these two respects unlike the atoms of any other element. He stated that atoms of the elements unite chemically in simple numerical ratios to form compounds. The best evidence for his theory was the experimentally verified law of simple multiple proportions, which gives a relation between the weights of two elements th
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Number of Protons/Electrons: 13 \nNumber of Neutrons: 14
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the answer is a, the number of outer shell electrons it can gain or lose.\n\nthia is because that outer electrons are the ones the define the atom in terms of bonding. \nmass nubmer and atomic number dont matter much [as lower level chemistry] for bonds. we know that the number of molecules it can form is infinite, and inner shells dont matter, leaving us wiht (A), the only right answer
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Atoms have what are called "orbitals" which are sorts of energy states that electrons can acheive.  A certain set of orbitals are considered the ground state, which is to say that a neutral atom (meaning the atom has as many electrons as protons) will be at its lowest energy state when all electrons occupy the ground state orbitals.  However, an electron can acquire extra energy which will raise the electron to a higher orbital.  This can be done by heat or light.  When an electron is elevated to a higher orbital, it is unstable, and it will eventually drop.  When it drops back down to groundd state, it will release a photon which has a specific amount of energy--the difference in enrgy between the higher and lower orital.\n\nEnergy in a photon relates to its wavelength, and wavelength relates to color.  Hence, for a given type of atom, the transition between two orbitals (which is set by the nucleus involving physical chemistry matters that are way too complex to speel out here) will always require a certain amount of energy, and the relaxation of an electron between those states will always release a photon of a specific color.
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Find the number of protons. Then number of electrons = number of protons.
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An electron/energy shell, is a group of atomic orbitals with the same value of the principal quantum number n. \nThus in a silicon atom (1s^2  2s^2 2p^6 3s^2 3p^2)  the number of energy shells with electrons in them is 3.\n\n(just for info: There are 5 occupied subshells (1s, 2s, 2p, 3s, 3p) and 8 occupied orbitals 1s 2s 2px 2py 2pz 3s 3px 3py, out of which the first 6 have 2 electrons and 3px and 3py have one electron each; Hund's rule doesn't allow an electron pair in 3px while the other 3p orbitals are empty)
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you can also write 1s2 2s2 2p4, for instance. In this way you are telling the number of electrons in each energy level (orbital), being 1s, 2s and 2p in this example the orbitals and being the number at the right the quantity of electrons there.
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Atomic Number 3\nhttp://www.jergym.hiedu.cz/~canovm/vyhledav/varianty/litva.gif
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The atomic number is the number of protons.
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The atomic number is representative of the number of protons in the nucleus.  The atomic mass is representative of the number of total particles in the nucleus, which is made up solely of protons and neutrons.  That means that (35 total particles)-(17 protons)=18 neutrons.
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Here's a great and simple explaination from Wikiopedia: \n\nIn atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (eg, a crystal).\n\nLike other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like properties. Formally, the quantum state of a particular electron is defined by its wavefunction, a complex-valued function of space and time. According to the Copenhagen interpretation of quantum mechanics, a particular electron is both "nowhere at all" and "everywhere all at once" until an act of measurement causes it to be detected. The probability that the act of measurement will detect the electron at a particular point in space is proportional to the square of the absolute value of the wavefunction at that point.\n\nElectrons are able to jump from one energy level to another by emission or absorption of a quantum of energy, in the form of a photon. Because of the Pauli exclusion principle, no more than two electrons may exist in a given atomic orbital; therefore an electron may only leap to another orbital if there is a vacancy there.\n\nKnowledge of the electron configuration of different atoms helps us understand the structure of the periodic table of elements. The concept is also useful for describing the chemical bonds that hold molecules together. And in a macro sense this same idea helps explain the peculiar properties of lasers and semiconductors\n\n\nThe other links are also good sources for review and expaination\n\nGood luck
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Don't understand your question. Did you proof read it? I bet you didn't, did you? \n\nDo you mean 'is quantum theory able to define a quantum of a quantum?'?\n\nIf so, the answer is no. A quantum is by definition the smallest step unit. The smallest unit of energy is h bar, which equals h over 2pi.
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Every atom has two unique numbers: Atomic Number (Z) and mass number (A). Atomic number Z represents the number of protons in the nucleus of an atom. Mass number A represents the number of neutrons and protons in the nucleus of an atom. When atoms are expressed on a periodic table, they are written with a number on the top and a number on the bottom. Z is written on the top and A is written on the bottom. Also when elements are represented with the name and a number on the upper lefthand side corner. This number represents the electrical charge of the atom. This is the number that tells us if the atom gained or gave away electrons.\n\nTo calculate the number of protons: Simply just look at the atomic number and it is the number of protons. For example Number of protons in a sodium atom is 11.(Z=11)\n\nTo calculate the number of electrons: Subtract electrical charge of the atom from the atomic number. For example Na+1 tells us that sodium atom gave an electron away. So 11-1=10 electrons present.\n\nBut the number of electrons is equal to the number of protons when the atom is not charged.\n\nTo calculate the number of neutrons: Subtract the atomic number from the mass number. For example, to find the number of neutrons in the nucleus of a sodium atom 23-11=12 neutrons.
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From Rule 1 and 2 we are ready to obtain an expression for one of the atomic properties, in this case is the velocity of the electron. Multiply both sides of Eq.(1) by r/mv, we obtain\n\nv= Z e2/4p eo mvr\n\nbut mvr in the denominator of this equation can be replaced nh/2 pi. we immediately have an explicit expression for the allowed values of velocity of the electron,\n\nv = Z e2/2peoh n ...(3)\n\nEq. (3) tells us that the velocity of the electron is directly proportional to the nuclear charge Z (in case of hydrogen Z=1) and inversely proportional to the principle quantum number n.\n\nvn = 2.188 x 106 m/s x (Z/n)\n\nFor H, n = 1.\n\n2,188,000 m/s = 4,894,000 miles per hour\n= 0.729 %c, c = speed of light in vacuum, 3 x 10^8 m/s
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If there are only 3 electrons, then the maximum number of orbitals in that subshell is 3. however, if you meant magnetic quantum number of +3 - as in ml = -3, -2, -1, 0, +1, +2, +3, then that's the f subshell which has 7 orbitals.