Atom

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1. ATOM Cline Reeve Venci L. Argallon

2. What is an ATOM?

3. An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.

4. Centuries of Discovery Greek Atom

5. Greeks thought that all matter is composed of 4 major elements: Air, Fire, Water and Earth or a combination of these for. Greeks used the term atom meaning “ indivisible” – cannot be divided.

6. Dalton Atom

7. All matter is made of  atoms .  Atoms  are indivisible and indestructible. All   atoms  of a given element are identical in mass and properties. Compounds are formed by a combination of two or more different kinds of  atoms . Hook and eye affair.

8. Thomson Atom

9. Bohr Atom

10. Neil Bohr improved Rutherford’s description of the atom Bohr’s model was a miniature of the solar system in which the electrons revolve around a specific the nucleus in prescribed orbits of energy levels.

11. Fundamental Particles of an Atom

12. Nucleons are made of quarks bound together by gluons

13. Particle Symbol Kilograms AMU Charge Comments Proton p 1.673 x 10 -27 1.00728 + Present in nucleus Neutron N 1.675 x 10 -27 1.00867 Present in nucleus Electron e - 9.109 x 10 -31 0.000549 - -from orbits around nuclei -ejected during beta decay Alpha-particle α 6.645 x 10 -27 4.003 + 2 2 protons and 2 neutrons Positron e + 9.109 x 10 -31 0.511 + Antiparticle of electron – produces annihilation radiation when both meet Neutrino v -ejected during beta decay

14. Orbital Shells

15. Maximum Electrons Per Shell 2n 2 n= shell number

16. An electron shell, n, cannot contain more than 2n 2 electrons where n is the shell number. The outer shell cannot contain more than 8 electrons.

17. Electron Binding Energy -The strength of attachment of a electron to the nucleus -Electron binding energy , also called ionization potential, is the  energy  required to remove an electron  from an atom, a molecule, or an ion . - Every element has their own unique EBE

18. Ionization - Removal of an electron from an atom

19. Excitation The orbital electron is promoted to a higher energy level within the atom Product is heat.

20. Valency The ability of one atom to join another. 2 Types Ionic Bonds – One or more electrons are transferred to another atom Covalent Bonds – Formed by sharing of electrons.

21. Covalent Bonding