Chapter 3 Atomic Structure. Chapter 3 Section 2 Atomic Structure.
Atomic structure – cont
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Atomic Structure – cont…
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Transcript of Atomic structure – cont
Atomic Structure – cont…
Isotopes Elements are defined by the number of protons (atomic #, Z). Atoms of an element with the same # of protons and electrons, but different # of neutrons.
◦ Same atomic # (Z) but different mass # (A)◦ Same chemical properties, however some are radioactive
Sonya Crider
Some materials are radioactive because the nucleus of each atom is unstable and gives out nuclear radiation in the form of alpha particles, beta particles or gamma rays. The radiation can be detected using a Geiger counter.
Isotopes - hydrogen
Isotopes - chlorineChlorine Protons Electrons Neutrons
n
Sonya Crider
Some materials are radioactive because the nucleus of each atom is unstable and gives out nuclear radiation in the form of alpha particles, beta particles or gamma rays. The radiation can be detected using a Geiger counter.
Isotopes - chlorineChlorine Protons Electrons Neutrons
n17 17
17 17
Sonya Crider
Some materials are radioactive because the nucleus of each atom is unstable and gives out nuclear radiation in the form of alpha particles, beta particles or gamma rays. The radiation can be detected using a Geiger counter.
Isotopes - chlorineChlorine Protons Electrons Neutrons
n17 17 35-17=18
17 17 37-17 = 20
Sonya Crider
Some materials are radioactive because the nucleus of each atom is unstable and gives out nuclear radiation in the form of alpha particles, beta particles or gamma rays. The radiation can be detected using a Geiger counter.
Isotopes
Practice Problems…..
Relative Atomic Mass (Ar)oHow we compare the mass of atomsoBased on Carbon atomoAtomic mass units (amu)
Element Ar
H 1C 12O 16Mg 24Cl 35.5
Relative Atomic Mass (Ar) Calculate the relative atomic mass (Ar) or Chlorine.
25 % 75 %
(75x35) + (25x37)= 35.5 amu 100
Arrangement of Electrons in AtomsElectrons move very fast around the nucleusIt is impossible to pinpoint their locationElectrons are arranged in energy levels and cannot be between them.
Arrangement of Electrons in Atoms 1st level – 2 2nd level – 8 3rd level – 18 (when 8 are present next two jump to level-4, then following return to level-3) 4th level - 2
Arrangement of Electrons in Atoms
Bohr-Rutherford Diagrams
