# Flashcards › Unit 2 cont.... Spectrum, Quantum

## A bright-line spectrum of an atom is caused by the energy released when electrons fall to a lower energy level Because excited hydrogen atom always produce the same line-emission spectrum, scientists concluded that hydrogen released photons of only certain energies The Bohr model of the atom was an attempt to explain hydrogen's line-emission spectrum If electrons in an atom have the lowest possible energies, the atom is in the ____ state Ground According to Bohr's theory, an excited atom would radiate energy Thomson created the ____ model of the atom Plum pudding Louis de Broglie's research suggested that electrons should be considered as waves confined to the space around an atomic nucleus The spin quantum number indicates that number of possible state for an ectron in an orbital is 2 Because of the property described by the spin quantum number, an electron behaves as though it were a magnet The number of possible orbital shapes for the third energy level is (hint, count how many orbitals have '3' in front of them) 3 For n=4, the number of possible orbital shapes is 4 For the f sublevel, the number of orbitals is 7 If n is the principal quantum number of a main energy level, the number of electron in that energy level is 2n^2 How many electrons are needed to completely fill the fourth energy level? 32 If 8 electrons completely fill a main energy level, what is n? 2 What is the total number of electrons needed to fill the first two main energy levels? 10 The statement that no two electrons in the same atom can have the same four quantum numbers is Pauli exclusion principle The atomic sublevel with the next highest energy after 4p is 5s The electron notation for aluminum is 1s^2 2s^2 2p^6 3s^2 3p^1 The number of electrons in the highest energy level of argon is 8 The product of the frequency and the wavelength of a wave equal the speed of the wave According to the particle model of light, certain kinds of light cannot eject electrons from metals because the energy of the light is too small The statement that we cannot know both the location and the speed of an electron at the same instant is what principle? Heisenburg Uncertainty Principle Wave function was described by Schrodinger Used a theoretical 'cat' experiment to explain his theory Schrodinger The rule that states that for an atom in the ground state, the number of unpaired electrons is the maximum possible and these unpaired electrons have the same spin Hund's rule Rule that states you must fill orbitals first with one electron (arrow up) before you add a partner (arrow down) Hund's rule Rule that states you must fill up the lower levels with electrons before adding them to higher energy levels Aufbau principle Second half of Unit 2 review. Focuses more on Chapters 3 & 4 in Holt's Modern Chemistry text