UNIT 1: The structure of matter: FQ3eso_U1_3: Electron configurations FÍSICA Y QUÍMICA 3º DE E.S.O. FIRST TERM UNIT 1: The structure of matter: FQ3eso_U1_3: Electron configurations Excited and Ground States Ions U.1_3 d1

2.7. Estructura atómica. Isótopos. Modelos atómicos. Bloque 2. La materia 2.7. Estructura atómica. Isótopos. Modelos atómicos. Criterios de evaluación C.E.2.6. Reconocer que los modelos atómicos son instrumentos interpretativos de las distintas teorías y la necesidad de su utilización para la comprensión de la estructura interna de la materia. CMCT, CAA. Estándares de aprendizaje evaluables EE.A.2.6.1. Representa el átomo, a partir del número atómico y el número másico, utilizando el modelo planetario. E.A.2.6.2. Describe las características de las partículas subatómicas básicas y su localización en el átomo. E.A.2.6.3. Relaciona la notación AZX con el número atómico, el número másico determinando el número de cada uno de los tipos de partículas subatómicas básicas. C.E.2.7. Analizar la utilidad científica y tecnológica de los isótopos radiactivos. CCL, CAA, CSC E.A.2.7.1. Explica en qué consiste un isótopo y comenta aplicaciones de los isótopos radiactivos, la problemática de los residuos originados y las soluciones para la gestión de los mismos. U.1_3 d2

Where are the electrons located in an atom? Electrons are located in the electron cloud that surrounds the nucleus U.1_3 d3

That is, electrons can be in orbits with different levels of energy What is the structure of the electron cloud? Scientists have found that electrons in the electron cloud have different amounts of energy. That is, electrons can be in orbits with different levels of energy U.1_3 d4

How are electrons arranged in energy levels? Energy levels or shells, are named using the numbers 1 to 7 or letters K. L, ... Energy levels 4 3 2 1 (3D view) Electrons occupy different energy levels, or shells U.1_3 d5

How are electrons arranged in energy levels? Every shell can hold a maximum number of electrons Electrons are not placed in this order in the atom U.1_3 d6

How are electrons arranged in energy levels? Every shell can hold a maximum number of electrons N = 2 x n 2 Number of electrons: N= 2 x n2 = 2 x 12 = 2 Shell K Energy level 1 Shell L Energy level 2 N= 2 x n2 = 2 x 22 = 8 Shell M Energy level 3 N= 2 x n2 = 2 x 32 = 18 Shell N Energy level 4 N= 2 x n2 = 2 x 42 = 32 U.1_3 d7

How are electrons arranged in energy levels? Electrons fill the energy levels starting with the inner level. Electron configuration for H: 1 E. Conf. for He: 2 U.1_3 d8

How are electrons arranged in energy levels? Electrons fill the energy levels starting with the inner level. Electron configuration for Li: 2, 1 E. Conf. for Ne: 2, 8 U.1_3 d9

How are electrons arranged in energy levels? Electron configurations: Electron configuration for O: 2, 6 E. Conf. for Mg: 2, 8, 2 U.1_3 d10

How are electrons arranged in energy levels? Electron configuration for Na: 2, 8, 1 E. Conf. for Cl: 2, 8, 7 U.1_3 d11

How are electrons arranged in energy levels? For example, the element sulfur has 16 electrons. Two electrons will be in energy level 1 and eight electrons will be in energy level 2. The rest of the electrons will be in energy level 3. U.1_3 d12

How are electrons arranged in energy levels? Excited and Ground States U.1_3 d13

How are electrons arranged in energy levels? Excited and Ground States Excited and Ground States Ground state: When all the electrons in an atom have the lowest possible energies Excited state: When an atom has absorbed energy so that its electrons have moved to orbits with higher energies U.1_3 d14

How are electrons arranged in energy levels? Electron configuration of the ground and excited states of Hydrogen Electron configuration of the ground state: H: 1 Electron configuration of the excited state: H: 0, 1 One electron in Shell K and no electron in shell L No electron in Shell K and one electron in shell L U.1_3 d15

How are electrons arranged in energy levels? Excited and Ground States Electron configuration of Sodium in the ground state is 2-8-1. One excited state of configuration could be 2-7-2. One electron has jumped from the second energy level to the third one Which of these is an excited state configuration? 2-8 2-8-6 1-8-4 U.1_3 d16

How many electrons are there in an atom? In a neutral atom, the number of electrons is equal to the number of protons. Sodium has an atomic number of 11, which means it has 11 protons and 11 electrons. U.1_3 d17

How many electrons are there in an atom? If a neutral atom, donates electrons, the number of protons is bigger than the number of remaining electrons. The atom is not neutral any more. It is positively charged. A cation is formed. ? U.1_3 d18

How many electrons are there in an atom? If a neutral atom, donates electrons, the number of protons is bigger than the number of remaining electrons. The atom is not neutral any more. It is positively charged. A positive ion or cation is formed. Na Na+ U.1_3 d19

How many electrons are there in an atom? If a neutral atom wins electrons, the number of protons is smaller than the number of total electrons. The atom is not neutral any more. It is negatively charged. A negative ion or anion is formed. ? Cl Cl- U.1_3 d20

How many electrons are there in an atom? If a neutral atom wins electrons, the number of protons is smaller than the number of total electrons. The atom is not neutral any more. It is negatively charged. A negative ion or anion is formed. F F- U.1_3 d21

U.1_3 d22