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October 29 th , 2015. Start Atomic Structure & Periodic Table. Bell Ringer Get homework out on your desk. Today’s Purpose:. Describe the present model of the atom. Matter and atoms. Matter: Anything that has mass and takes up space. All matter is made up of atoms. Matter and atoms.
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October 29th, 2015 • Start Atomic Structure & Periodic Table Bell Ringer • Get homework out on your desk.
Today’s Purpose: • Describe the present model of the atom.
Matter and atoms Matter: • Anything that has mass and takes up space. • All matter is made up of atoms.
Matter and atoms Atom: • Basic building block of matter • Cannot be broken down further without changing the properties of that element • The smallest unit of an element
Different types of atoms are called elements. All matter is made of the atoms of approximately 118 elements. Atom Concentrations by Mass Earth’s Crust I r on 5 % A luminum 8 % O the r 12% O x y gen 47% S ili c o n 28% Humans Nit r o gen 3 % O ther 3% H y d r o gen 10 % C ar b o n O x y gen 23% 61% SOU R CE : C R C H andb o o k o f Ch e mis t r y and P h y si c s
Chemical symbols A chemical symbol is an abbreviated way to write the name of an element. For example: C = Carbon H = Hydrogen Fe = Iron
Chemical symbols Chemical symbols always consist of one capital letter or a capital letter plus one or two small letters. C Cl CS Cs
nucleus proton neutron electron cloud Atoms are made of protons, neutrons, and electrons. Nucleus – the central region of an atom where most of the atom’s mass is found in protons and neutrons.
Atoms are mostly empty space. The radius of a atom is about 100,000 times larger than the radius of its nucleus. If a basketball represented a nucleus…that atom would have a radius of 7.5 miles!
Protons, Neutrons, Electrons Protons: Positive (+) charge, mass = 1, indicates identity of atom Found inside nucleus Neutrons: Neutral (0) charge, mass = 1 Found outside nucleus Electrons: Negative (-)charge, mass = 1/2000
Protons, Neutrons, Electrons 5 B Boron Atomic Number = Number of protons Boron has 5 protons
Protons, Neutrons, Electrons Mass Number = Protons + Neutrons
N +3 7 Protons = 7 + Electrons = ? Charge 4 Charge = +3 +3
Protons = 35 + Electrons = ? Charge Br -1 35 36 Charge = -1
Protons = 25 + Electrons = ? Charge Mn 25 25 Charge = 0
Matter and atoms Nucleus (+ charge) Proton (+) Neutron (No charge) Electrons (- charge) - “orbit” the nucleus
Models of the atom Electron Cloud!
Assignments • Book reading chapter. • Atomic Structure (ws) • Quiz on elements Wednesday, November 4th