Applied Chapter 3.2 : Structure of Atoms
- 1. Chapter 3.2Structure of Atoms
- 2. Objective 1:Describe the evidence for the existence of electrons, protons, and neutrons, and describe the properties of these subatomic particles.Define atom: smallest particle of an element that retains the chemical properties of that element.Subatomic particles:ProtonsNeutronsElectrons
- 3. Discovery of the ElectronLate 1800’s – J.J. Thomson discovered the electron through experiments with cathode-ray tubes.Electron PropertiesRelative Charge Mass Number actual mass- 1 0 9.109 x 10-31 kgPlum Pudding Model of atom
- 4. Discovery of Atomic NucleusIn 1911 – Ernest Rutherford – Gold Foil ExperimentShowed that there was a small – dense positively charged nucleus of an atom.Proton PropertiesRelative Charge Mass Number actual mass+ 1 1 1.673 x 10-27 kg
- 5. NeutronsDiscovered in 1932 by James ChadwickBritish ScientistNeutron PropertiesRelative Charge Mass Number actual mass0 1 1.675 x 10-27 kg
- 6. The AtomNuclear Forces – Short range proton-neutron, proton-proton, and neutron-neutron forces that hold the nuclear particles together Sizes of Atoms
- 7. Nucleus compared to rest of atom - approximately size of marble compared to a large football stadium.
- 8. Atom is mostly empty spaceObjective 2Discuss atoms of different elements in terms of their numbers of electrons, protons, and neutrons, and define the terms atomic number and mass numberAtomic Number (Symbol – Z)Number of protons in nucleus of atomDetermines the identity of the atom!!!!!C - 6He - ___F - ___Pb - ___Use periodic table to find these!Since atoms are neutral, atomic number is also number of electronsSo C also has 6 electronsHe - ____ electrons
- 9. Objective 3Define isotope, and determine the number of particles in the nucleus of an atom.IsotopesAll Hydrogen atoms contain 1 proton
- 10. Many naturally occurring elements can contain different numbers of neutrons.
- 11. Isotope – at0ms of the same element that have different masses.nnnProtium99.985 %Deuterium 0.015 % TritiumTraceThree isotopes of Hydrogen
- 12. Mass NumberMass number – total number of protons and neutrons in the nucleus of an isotope
- 13. Symbol – A
- 14. Protium has 1 proton and 0 neutrons
- 15. Mass number = #p + #n
- 18. What is the mass number deuterium and tritium?
- 19. Find on periodic tableDetermine the number of particles in an atomHow many protons, electrons, and neutrons are present in an atom of copper whose atomic number is 29 and whose mass number is 64?How many protons and electrons are in an atom of sodium whose atomic number is 11?An atom has 13 protons and 14 neutrons. What is its mass number?Calculate the mass number for an atom that has 45 neutrons and 35 electrons.
- 21. Name of atom – mass number
- 22. Uranium - 235
- 23. Nuclear symbol
- 24. A X A : mass number, Z : atomic number, X : symbol of element
- 25. 235UZ92Number of protons Neutrons Electrons 92 143 92Nuclide – general term for any isotope of any elementDetermine the number of particles in isotopes.Calculate the numbers of protons, electrons, and neutrons in oxygen – 17 and in oxygen – 18.Chlorine has two stable isotopes, chlorine – 35 and chlorine – 37. The atomic number of chlorine is 17. Calculate the numbers of protons, neutrons, and electrons each isotope has.Calculate the numbers of protons, electrons, and neutrons for each of the following isotopes of calcium : Ca and Ca42442020