Atomic Structure Nucleons Particles in the nucleus of

Atomic Structure • Nucleons – Particles in the nucleus of atom • Proton • Neutron • Atomic Number – Number of protons in the atom of an element • Neutral atom • # of protons (+) = # of electrons (-) Episode 302

Isotope • Atoms of an element the have a different number of neutrons (different mass) • Isotopes of Hydrogen – 1 • 1 proton and 0 neutrons – Hydrogen – 2 • 1 proton and 1 neutron http: //www. youtube. com/watch? v=z. EX 2 a. Gp. IDBY&feature=re lated – Hydrogen – 3 • 1 proton and 2 neutrons • Mass Number – Total number in protons and neutrons in an atom Episode 302

• Examples – Carbon – 14 14 6 C 20 10 Ne – Neon – 20 Particle Charge Mass Location Proton +1 neutral -1 1 amu 0 amu nucleus e- cloud Neutron Electron • Atomic Mass – Weighted average of the masses of all the element’s isotopes Episode 302

Subatomic Particles # of protons = atomic number # of electrons = atomic number # of neutrons = mass number – atomic number Round the average atomic 3 protons 3 electrons mass b/c its mass is closest to the most abundant ? neutrons isotope. 7 – 3 = 4 neutrons 26 protons 26 electrons 56 – 26 = 30 neutrons Episode 302

• Carbon – 14 – Find atomic number • 6 protons • 6 electrons – Mass number – atomic number • 14 – 6 = 8 neutrons • Oxygen – 17 – 8 protons – 8 electrons – 17 – 8 = 9 neutrons Episode 302

15 7 N 7 protons 7 electrons 15 – 7 = 8 neutrons 2 protons 2 electrons 4 – 2 = 2 neutrons Episode 302