3. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
4. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
6. What is an Atom? Atoms are the smallest particle of an element.
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8. The Story of Atoms Atoms have positive charges concentrated in their small nucleus! There are neutrons! Ernest Rutherford (1871 -1937) Democritus 460 BC Sir James Chadwick (1891 -1974) Joseph John Thompson (1856-1940) Niels Bohr (1885-1962) ATOMA PLUM PUDDING MODEL 1898
9. Bohr’s Atom electrons in orbits nucleus http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/atom.swf
10. Structure of Atom An atom consists mostly of empty space. A positively charged nucleus, densely concentrated in the centre. The nucleus contains protons and neutrons, which are tightly packed. Negatively charged electrons move around the nucleus in fixed orbits or paths. 10
11. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
12. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
16. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
17. Interpreting Chemical Symbol O 16 Mass=P+N mass number (nucleon number) mass number is the total number of protons and neutrons in an atom. Number of neutrons in the oxygen atom is: 16 – 8 = 8. chemical symbol 8 proton number (atomic number) atomic number (proton number) is the number of protons in an atom. Each oxygen atom has 8 protons. As the number of electrons is equal to the number of protons in an atom, each oxygen atom contains 8 electrons. P=E No. of protons= no. of electrons 16
18. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
19. Recap on Atomic Structure Structure of atom B. Relative masses and charges of proton, neutron and electron C. Chemical symbols D. Electronic configuration
22. Summary for Atomic Structure (I) The structure of an atom The relative charges & relative masses of proton, neutron & electron Defined mass number & atomic number Learnt how to interpret chemical symbols The electronic configuration of atoms
28. Definition of Isotopes Isotopes are atoms of the same element which contains the same number of protons but different number of neutrons. Same P different n
29. Isotopes mass number O O 17 O 18 16 proton number 8 8 8 Oxygen-17 Oxygen-18 Oxygen-16 n = 8 n = 17 – 8 = 9 n = 18 – 8 = 10
30. Isotopes Isotopes have the same chemical properties but slightly different physical properties
31. Q. Do all Isotopes of the same element have the same mass?
34. Uses of Radioactive Isotopes Food irradiation Archaeological dating (carbon-dating) Smoke detectors Radioactive tracers
35. Summary Recap on Atomic Structure 1. Definition of Isotopes 2. Uses of Isotopes
36. Definition of Isotopes Isotopes are atoms of the same element which contains the same number of protons but different number of neutrons. Same P different n
Pace;content; more interactiveHow many monomers to make polymer… molecular weight…Polymerisation does not only occur at high temperature… gas phase high presesure (polyethene)Dun generalize. High pressure for high density polymers… lower lower density.. Branched/unbranched…? Carbo, proteins n DNA are natural polymers… fats are not… C to C.. Cations to cathodesElectrolytes are salts mols that dissolve in water to ions that can conduct electrons..
Where in the atoms are these sub-atomic particles found?
Pace;content; more interactiveHow many monomers to make polymer… molecular weight…Polymerisation does not only occur at high temperature… gas phase high presesure (polyethene)Dun generalize. High pressure for high density polymers… lower lower density.. Branched/unbranched…? Carbo, proteins n DNA are natural polymers… fats are not… C to C.. Cations to cathodesElectrolytes are salts mols that dissolve in water to ions that can conduct electrons..