NATS 1675 Lecture Notes - Lecture 5: Covalent Bond, Valence Electron, Atomic Orbital
31 May 2016
School
Department
Course
Professor
Document Summary
Lecture 6 human development at the molecular level. Consist of 2 areas and 3 subatomic particles: central nucleus. All atoms of an element have the same number. Protons + neutrons = 1 atomic mass unit (amu). Atoms tend to lose, gain or share electrons until they are surrounded by 8 valence electrons. First shell: closest to nucleus, lowest energy, up to 2 electrons. Second shell: holds up to 8 electrons. Third shell: holds up to 8 electrons. Answers slide 11: carbon, nitrogen, oxygen, hydrogen, proton, neutron, electron, number of protons. At the bottom left of atomic symbol: the # protons + # neutrons. Upper left of atomic symbol: same number of electrons as protons. Isotopes = same number of protons but different number of neutrons. Atoms react with other elements to form compounds and molecules. Groups of 2 or more atoms held together. Some molecules are made up of only one element i. e. , oxygen= 2 atoms of oxygen (o2).
