2 Learning ObjectivesLearning ObjectivesApply an understanding of the structure of the atom. Be able to interpret numbers of subatomic particles making up each atom.
3 Atomic ModelsThis model of the atom may look familiar to you. This is the Bohr model. In this model, the nucleus is orbited by electrons, which are in different energy levels.A model uses familiar ideas to explain unfamiliar facts observed in nature.A model can be changed as new information is collected.
5 ATOMIC STRUCTUREParticleChargeMassproton+ ve charge1neutronNo charge1electron-ve chargenil
6 Atoms are the smallest particles of an element that retains the chemical properties of that element Parts:Nucleus – small region in the center of the atom.(+ charged protons, = charged neutrons)Electron Cloud – large region, compared to nucleus, where electrons are found.
7 Size of nucleus vs. electron cloud If an atom was the size of a sports stadium, the nucleus would be the size of a marble!Subatomic Particles:Protons : + charge, relative mass = atomic mass units (amu); round to 1Neutrons: = charge, relative mass = atomic mass units (amu); round to 1Electrons: - charge, relative mass = atomic mass units (amu); round to 0 (not factored in when figuring total mass of an atom)
8 IsotopesAtoms with the same number of protons & electrons but a different number of neutrons.They are the same element, but have different masses.All isotopes are used to calculate atomic mass (reason why weight is a decimal).Most elements consist of a mixture of isotopes.
9 Atomic NumberNumber of protons in the nucleus (also the number of electrons)Typically the number on top of the symbol on the Periodic Table.13Atomic Number26.981
10 Mass Number Number of protons + number of neutrons in an atom. When solving for number of neutrons: round mass number properly, subtract atomic number from mass number.
11 Mass NumberMass number is the number of protons and neutrons in the nucleus of an isotope:Mass # = p+ + n0Nuclidep+n0e-Mass #Oxygen -10-3342- 3115188818Arsenic753375Phosphorus161531
12 Complete SymbolsContain the symbol of the element, the mass number and the atomic number.XSuperscript →AtomicnumberSubscript →Massnumber
13 number of electrons = number of protons ATOMIC STRUCTUREHe2Atomic numberthe number of protons in an atom4Atomic massthe number of protons andneutrons in an atomnumber of electrons = number of protons
14 Modern Atomic Structure electrons move so fast they look like a cloud and difficult to pinpoint
16 ATOMIC STRUCTUREElectrons are arranged in Energy Levels or Shells around the nucleus of an atom.first shell a maximum of 2 electronssecond shell a maximum of 8 electronsthird shell a maximum of 8 electrons
17 Electrons are in energy levels ShellsspdfgTotal12683101841432
19 N DOT & CROSS DIAGRAMS Nitrogen With Dot & Cross diagrams elements and compounds are represented by Dots or Crosses to show electrons, and circles to show the shells. For example;XNitrogenN7XXNXX14XX
20 ELECTRONIC CONFIGURATION With electronic configuration elements are represented numerically by the number of electrons in their shells and number of shells. For example;Nitrogenconfiguration = 2 , 572 in 1st shell5 in 2nd shellN= 714
21 N DOT & CROSS DIAGRAMS Nitrogen With Dot & Cross diagrams elements and compounds are represented by Dots or Crosses to show electrons, and circles to show the shells. For example;XNitrogenN7XXNXX14XX
22 DOT & CROSS DIAGRAMS O Cl Draw the Dot & Cross diagrams for the following elements;X817XOCla)b)X35X16XXXXXClXXXXXXXOXXXXXXXXXX
23 Pop QUIZ How many protons does Helium have How many electrons does Zinc have3. Silver has ____electrons4. Magnesium____electrons5. Uranium____electrons6. Kryption ______protons7. Aluminium____electrons8. Bromine ____mass9. Calcium ____electrons10. Sodium has ______protons
24 ATOMIC QUIZ 2: Written answers What is meant when an atom is said to be in its ground state?3. The subatomic particle(s) found in the nucleus of an atom are5. What is the maximum number of electrons that can occupy an atomic orbital?8. In which way do isotopes of an element differ?9. Calcium's atomic number is 20. What does that that tell us about a calcium atom?10. What is ALWAYS true regarding atoms of two different elements?
25 Answers1. What is meant when an atom is said to be in its ground state? CORRECT: The state an atom is found naturally.3. The subatomic particle(s) found in the nucleus of an atom areCORRECT: protons and neutrons.5. What is the maximum number of electrons that can occupy an atomic orbital?CORRECT: 2, 6, 10, 148. In which way do isotopes of an element differ?CORRECT: number of neutrons in the atom9. Calcium's atomic number is 20. What does that that tell us about a calcium atom?CORRECT: It has 20 protons.10. What is ALWAYS true regarding atoms of two different elements?CORRECT: They have different numbers of protons.
26 ELECTRONIC CONFIGURATION Write the electronic configuration for the following elements;20118NaOCaa)b)c)1623402,8,8,22,8,12,617145ClSiBd)e)f)1135282,8,72,8,42,3
27 ELECTRONIC CONFIGURATION Write the name, electronic configuration and diagram for the following elements;412Ca20BeMg2)3)1)408242,8,22,8,8,22,261432Ge4)C5)Si6)7212282,42,8,42,8,18,4315Ga13B7)8)Al9)1069262,8,18,32,8,32,335F917Br10)11)Cl12)1879342,72,8,72,8,18,7
28 DO YOU REMEMBER ? The Atomic Number of an atom is the............ The Atomic Mass of an atom isProtons in the nucleus equals the.....The number of Electrons =Electrons orbit the nucleus in _______= number of protons in the nucleus.= number of Protons + Neutrons in the nucleus.= Number of Electrons.Number of Protonsshells.
29 Structure of Subatomic Particles Subatomic particles composed of fast moving points of energy called quarksQuark Calculations (for protons and neutrons)Each proton is 2 up quarks and 1 down quark2(2/3) – 1(1/3) = 4/3 – 1/3 = 3/3 or +1Each neutron is 2 down quarks and 1 up quark2(-1/3) + 2/3 = 0Each electron is composed of 2 down quarks3(-1/3) = -1