Atomic Theory

• Democritus & Leucippus - said that all matter is composed of atom in the world
• John Dalton - presented evidence that atoms are the smallest particle
• James Chadwick - discovered neutrons
• Neutrons - is a particle with no electric charge and is a part of an atom
• Eugen Goldstein - discovered the evidence of protons, the positively charged protons which is a part of an atom
• JJ. Thomson - experimented and found out about electrons in atoms
• Plum Pudding Model - created by JJ. Thomson, this model proved that the atom is a sphere of positve and negative charged electrons
• Ernest Rutherford - decribed the model as the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass are charged
• Ernest Rutherford - he compared the electrons as a planet orbiting the sun
• Neils Bohr - proposed a model of the atom which the electrons can only orbit a certain way/times
• SUBATOMIC PARTICLES: Neutrons, Electrons, & Protons
• Electrons (e^-) - 9.109x10^-28
• Protons (p^+) - 1.672x10^-24
• Neutrons (n^0) - 1.675x10^-24
• Nucleons - protons and neutrons. They are called this because they can be found at the nucleus or the center of the atom
• Electrons - is the lightest and its mass is negligible (walang kwenta)
• Protons and neutrons - are massive
• Protons - the number of protons is the same as the atomic number
• Electrons - same number of atoms as protons
• Neutrons - neutral particle
• Neutrons - to get the value, you need to subratract the atomic mass and the number of protons
• Atomic Number - a unique number of the element
• Isotopes - atoms of an element that have the same atomic number but not mass
• Mass number - to get this you need to round off the atomic weight to the nearest whole number
• Element - a neutral atom which means it has the same number of protons and electrons
• ION - is an electric charged particle that is the result from the charge of an electron since it has the tendency to move from one to another
• Anion - negatively charged ION
• Cation - positively charged ION
• When the electrons are changed then the protons stays the same