Wave Mechanical Model of Atom. Electron Configuration Pictures. The energy of the level increases as the value of n increases.

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1 Wave Mechanical Model of Atom Electron Configuration Pictures Mrs. Dormer Organic Chemistry Atoms have a series of energy levels called principal energy levels These are designated by whole numbers (symbolized by n) n can equal 1, 2, 3, 4. Level 1 corresponds to n = 1, level 2 corresponds to n = 2 and so on. The energy of the level increases as the value of n increases. Each principal energy level contains one or more types of orbitals called sublevels. Sublevels are identified by letters s, p, d, f The number of sublevels present in a given principal energy level equals n. For example, level 1 contains one sublevel The 1s orbital Level 2 contains two sublevels (two types of orbitals) The 2s orbital and three 2p orbitals 1

2 The n value is always used to level the orbitals of a given principal level and is followed by a letter that indicates the type (shape) of the orbital. For example, the designation 3p means an orbital in level 3 that has two lobes (a p orbital always has two lobes). 2

3 An orbital can be empty or it can contain one or two electrons, but never more than two. If two electrons occupy the same orbital, they must have opposite spins. The shape of an orbital does not indicate the details of electron movement. It indicates the probability distribution for an electron residing in that orbital. 3

4 1. Atoms have a series of energy levels called principal energy levels which are designated by whole numbers symbolized by n. Level 1 corresponds to n = 1, level 2 corresponds to n = 2, and so on. 2. The energy of the level increases as the value of n increases. 3. Each principal energy level contains one or more types of orbitals called sublevels. 4. The number of sublevels present in a given principal energy level equals n. For example, level 1 contains one sublevel (1s); level 2 contains two sublevels, the 2s orbital and the three 2p orbitals. n Sublevels (Types of Orbitals) Present 1 1s (1) 2 2s (1) 2p (3) 3 3s (1) 3p (3) 3d (5) 4 4s (1) 4p (3) 4d (5) 4f (7) 4

5 5. The n value is always used to label the orbitals of a given principal level and is followed by a letter that indicates the type (shape) of the orbital. For example, the designation 3p means an orbital in level 3 that has two lobes. 6. An orbital can be empty or it can contain one or two electrons, but never more than two. If two electrons occupy the same orbital, they must have opposite spins. 7. The shape of an orbital does not indicate the details of electron movement. It indicates the probability distribution for an electron residing in that orbital. 1) An s orbital is always spherical in shape. True. The size of the sphere increases as n increases, but the shape is always spherical. 2) The 2s orbital is the same size as the 3s orbital. False. The 3s orbital is larger (the electron is farther from the nucleus on average) than the 2s orbital. 5

6 3) The number of lobes on a p orbital increases as n increases. That is, a 3p orbital has more lobes than a 2p orbital. False. A p orbital always has two lobes. 4) Level 1 has one s orbital, level 2 has two s orbitals, level 3 has three s orbitals, and so on. 5) The electron path is indicated by the surface of the orbital. False. Each principal energy level has only one s orbital. False. The electron is somewhere inside the orbital surface 90% of the time. The electron does not move around on this surface. 6) The shape of a given type of orbital changes as n increases. 7) The number of types of orbitals in a given energy level is the same as the value of n. False. The shape of a given orbital stays the same while the size increases. True. For example, in n = 2 there are two types of orbitals (s and p). 6

7 8) The hydrogen atom has a 3s orbital. True. There are no electrons in the 3s orbital for a hydrogen atom in its lowest energy state, but the orbital is a potential space, not a physical structure. 7

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