Transcript Chapter 17
Chapter 17 Properties of Atoms and the Periodic Table Section 1 – Structure of the Atom Look at elements and their symbols What’s in an atom? Atom: smallest piece of matter that still is the __________________ Nucleus: ______________________ charged center of atom containing – Protons: particle with _________ charge – Neutrons: particle with ________ charge Electrons: surround nucleus in cloud and have ______ charge Even smaller… ______________: make up protons and neutrons NOT electrons Found using a __________________ accelerator – Speed up particles and ______________ them into each other – Found ____ quarks Models Represent things that are hard to _______________ Model of the _______________ has changed many times Pg. 510 in book Today’s model of atom Electron ________________ model: nucleus in middle and cloud around nucleus where electrons are most ________________ found Section 2 Atomic Masses Masses of Atoms Nucleus has most of mass – _______________ : 1.6726 x 10-24 g – Neutron : 1.6749 x 10-24 g – _______________: 9.1093 x 10-28 g Mass of proton and neutron are about ________________ times bigger than electron!! Atomic Mass Need ______________ numbers for masses Atomic ___________ Unit (amu) Proton: 1 amu Neutron: ___ amu Electron ~ negligible Protons Identify Element Each element has different # of ____________________ The number of protons tells you what type of _____________________ you have Atomic Number: the number of _____________ Mass Number Mass Number: ____________ of protons and neutrons # of neutrons = mass # - __________ # Carbon – 12 and Carbon – 14 Mass Number Mass Number How many neutrons are in the Carbon14 atom? Sodium has a mass number of 23. How many protons and neutrons does it have? Copper – 63: how many protons and neutrons? Isotopes Def: atoms of the same element that have different # of ____________ Isotopes: Boron – 10 and Boron – 11 Average Atomic Mass: ________________ average mass of mixture of isotopes Calculating Average Atomic Mass Four out of five boron atoms are boron11 and one out of five are boron-10. What is the AAM? Section 3 The Periodic Table Organizing the Elements __________________ – repeated in a pattern Late 1800s – Dimitri Mendeleev – Russian – organized elements by increasing ______________ Discovered a pattern with chemical __________________, they repeated Periodic Mendeleev’s Periodic Table Current Periodic Table 1913 – Henry Moseley – English – organized elements by increasing ________________________ The Atom and the Periodic Table Vertical columns = _______________ / Families Use A group numbering Families have _________________ properties Location of Electrons In neutral atom, # of _______________ = # of electrons Energy levels – close to nucleus = ___________ energy – farther away = _____________ energy Energy Levels and Electrons Same group = same # of _________ in _______________ energy level Energy levels are 1 – _____ Filled outer energy level = ________ Levels 3 and higher have __________ sub-levels Energy Levels and Electrons Horizontal rows = _____________ Increase by 1 p+ and 1 e- as you move ______________ Each row ends with atom with _______________ outer energy level Electron Dot Diagrams Group #s = # ________________ e-s (outer e-s) Def: uses the element _____________ and dots to represent outermost ____________________ Atoms bond to get a _______________ outer energy level Which groups would likely react? Regions of the Periodic Table Metals, Non-metals, and Metalloids Metals Conductors of ___________ and electricity Luster/___________ Mostly solid Nonmetals _________ conductors of heat and electricity Many are gases Solids are _________ Metalloids • _________________ of heat and electricity