Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Pre-AP Chemistry Name _______________________________ Period: ______________ 2 • Atomic & Molecular Structure Atomic Theory Notes #1 Relevant textbook pages: 65 - 85 Section Objectives Students know protons and neutrons in the nucleus are held together by nuclear forces that overcome the electromagnetic repulsion between the protons. (11a) Students know the nucleus of the atom is much smaller than the atom yet contains most of its mass. (1e) Students recognize the usefulness and limitations of models and theories as scientific representations of reality. (I&E 1g) Students recognize the cumulative nature of scientific evidence. (I&E 1k) Dalton’s Theory A Summary of Dalton’s Atomic Theory: 1. An element is composed of tiny, _____________, _____________ particles called _______. 2. All atoms of an element are _____________and have the same _____________. 3. Atoms of different _____________combine to form _____________. 4. Compounds contain atoms in small _____________number ratios. Atoms can combine in more than one _____________to form different _____________. Good stuff: Part 3: Chemical reactions occur when atoms are joined, _____________or _____________ Part 4: _____________combine in whole number ratios Not so good stuff: Part 1: Atoms _____________be separated: _____________particles Part 2: All atoms _____________identical: _____________ Thomson Model of the Atom Thomson Atomic Theory (1903) Post discovery of the _____________ Also known as: the _____________Pudding model Good stuff: accounts for both _____________and _____________ Not so good stuff: Nothing about the _____________or the _____________of p+, e-, or no Rutherford Model of the Atom Ernest Rutherford Post discovery of the _____________ A.K.A. _____________atomic model 1 Proposed two things: Nuclear atom, with e- surrounding the _____________center _____________nucleus, with rest of atom mostly _____________space Problem: No _____________as to why _____________do not collapse onto the _____________. Now we know: The nucleus is held together by the _________________________________ Rutherford’s Gold Foil Experiment Rutherford fired _____________particles at thin gold _____________. If the “plum pudding” model of the atom was correct, most alpha particles should _____________. However, _____________of the alpha particles were _____________backwards. Rutherford’s Gold Foil Experiment Rutherford’s Findings The nucleus is small, dense & _____________charged Atom is mostly __________________________ The nucleus made of __________________________ The _____________ around the nucleus Called the “_______________________________________” Subatomic Particles 2 PAP Chemistry Name _______________________________ Period: ______________ 2 • Atomic & Molecular Structure Atomic Structure Notes #2 Section Objectives Students know how to relate the position of an element in the periodic table to its atomic number and atomic mass. (1a) Students know the nucleus of the atom is much smaller than the atom yet contains most of its mass. (1e) Students know some naturally occurring isotopes of elements are radioactive, as are isotopes formed in nuclear reactions. (11c) Atomic Number Atoms are composed of __________________, ___________________, and __________________ Elements are different because they contain different numbers of ________________________ The “atomic number” of an element is the number of ________________________in the nucleus # protons in an atom = # ________________________ Give the number of protons and electrons for: Carbon Phosphorus Gold Mass Number Mass number is the number of protons and neutrons in the nucleus of an atom: Complete Symbols Contain the symbol of the element, the mass number and the atomic number. Neutrons Give the number of neutrons for: Carbon Phosphorus Uranium Hydrogen 3 Symbols Find each of these: a) number of protons b) number of neutrons c) number of electrons 80 35 Br d) Atomic number e) Mass Number If an element has an atomic number of 34 and a mass number of 78, what is the: a) number of protons b) number of neutrons c) number of electrons d) complete symbol 4 If an element has 91 protons and 140 neutrons what is the a) Atomic number b) Mass number c) number of electrons d) complete symbol If an element has 78 electrons and 117 neutrons what is the f) Atomic number g) Mass number h) number of protons i) complete symbol Isotopes Dalton was wrong about all atoms of the same element being __________________ Atoms of the same element can have different numbers of __________________. Thus, different __________________numbers. These are called __________________. Naming Isotopes We can also put the mass number after the name of the element: carbon-13 carbon-14 uranium-235 2H 15N