General Chemistry 1 Atomic Structure.pptx

ATOMIC STRUCTURE

1. General Chemistry 1

2. The Atomic Structure Atom -is the building block of matter. - Is also made up of smaller components called subatomic particles .

3. Atomic Theory -Proposed by John Dalton All matter is made up of atoms. An element is made up of one kind of atom. A compound is made up of a combination of different kinds of atoms following a specific ration. Law of Definite Proportions – states that elements form compounds in fixed proportions by mass, and by extension, by atoms. Law of Multiple Proportions – atoms can combine in different ratios leading to the formations of different compounds. Ex. Carbon monoxide and Carbon dioxide.

4. 4. An atom cannot be created nor destroyed. When substances chemically combine or decompose, the atoms involved in these reactions are still retained and because of this, the combined masses of these atoms are also retained. This is in accordance with the Law of Conservation of Mass.

5. Subatomic Particles Electron -Discovered by J.J Thomson -Thomson proposed the Plum-Pudding Model Plum-Pudding Model – describe the atom as a jelly like positive matter with negatively charged particles embedded in it like pudding with plums.

6. Proton Discovered by Ernest Rutherford with his Gold Foil Experiment. Proposed Nuclear Model . Positively Charged

7. The Neutron Discovered by James Chadwick Has the mass as that of a proton by electrically neutral . The protons and neutrons are located in the nucleus of the atom are collectively called nucleons .

8. Particle Symbol Charge, Column Electron e- -1.602x10^-19 9.108 x 10^-28 Proton p+ 1.602x10^-19 1.673 x 10^-24 Neutron n 1.675 x 10^-34

9. Atoms and the Elements

10. Atomic Symbol C Number of Protons

11. Atomic number – is the number of protons, which is denoted by the symbol Z -the atomic number gives atom its identity. Mass number – the sum of protons and neutrons, denoted by the symbol A. A = # of protons + # of neutrons.