The Atom What is Matter anything that has

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The Atom

The Atom

What is Matter? • anything that has ____ and takes up ____ • matter

What is Matter? • anything that has ____ and takes up ____ • matter is made up of ____

(2 Volunteers) How Small are Atoms? • It would take a stack of about

(2 Volunteers) How Small are Atoms? • It would take a stack of about 50, 000 aluminum atoms to equal the thickness of a sheet of aluminum foil from your kitchen • If you could enlarge a penny until it was as wide as the US, each of its atoms would be only about 3 cm in diameter – about the size of a ping pong ball • A human hair is about 1 million carbon atoms wide • A typical human cell contains roughly 1 trillion atoms • A speck of dust might contain 3 x 1012 (3 trillion) atoms • It would take you around 500 years to count the number of atoms in a grain of salt

Activity: • Rip or cut a standard piece of paper in half as many

Activity: • Rip or cut a standard piece of paper in half as many times as you can. Class Discussion: • How many cuts were we able to make? ____ • Do you think we could keep cutting the paper forever? Why or why not? • You would have to cut the paper in half around thirty-one (31) times to get to the size of any atom.

What is an Atom? • the smallest unit into which matter can be __________

What is an Atom? • the smallest unit into which matter can be __________ • ______________ of all matter • comprised of a ________(at it’s center) and an ______________ (surrounding the nucleus) • made up of ______ _particles What are Subatomic Particles? • smaller than an atom • __________________ • _________

Early Atom Models: What is the Rutherford Model? • mostly empty • small, positively

Early Atom Models: What is the Rutherford Model? • mostly empty • small, positively (+) charged nucleus • contained protons and electrons scattered around the outside

Early Atom Models: What is the Bohr Model? • electrons (-) move in definite

Early Atom Models: What is the Bohr Model? • electrons (-) move in definite ______ around the nucleus • Nucleus is made of _______ (+) and ________ (neutral).

Modern Atom Model: What is the The Electron Cloud Model? • sometimes called the

Modern Atom Model: What is the The Electron Cloud Model? • sometimes called the wave model • spherical cloud of varying density • varying density shows where an electron is more or less likely to be • The Bohr Model is still used to help explain characteristics of the atom.

What are Protons? - ++ + + + - - + • _______ charged

What are Protons? - ++ + + + - - + • _______ charged particles (+) - • help make up the ______ of the atom • equal to the _________ of the atom • contribute to the ________ • equal to the ______ of ________ in a neutral atom.

What are Neutrons? - ++ + + + - - - • ______ particles;

What are Neutrons? - ++ + + + - - - • ______ particles; have no electric charge • help make up the nucleus of the atom • contribute to the __________.

What are Electrons? - - - • found _______ the nucleus of the atom

What are Electrons? - - - • found _______ the nucleus of the atom in the electron _______. ++ + + + - - • _______ charged particles (-) - • each orbital/level can hold a maximum number of electrons • 1 st orbital = _____ • 2 nd orbital = _____ • 3 rd orbital = _____

What are Electrons? - ++ + + + - - - • move so

What are Electrons? - ++ + + + - - - • move so rapidly around the nucleus that they create an ___________ - • mass is insignificant when compared to protons and neutrons • equal to the _____ of ___________ in a neutral atom • involved in the formation of chemical bonds

What are Valence • found in the outermost energy level of the Electrons? electron

What are Valence • found in the outermost energy level of the Electrons? electron cloud (called the _______) • involved in bonding • determine the chemical properties of an element

How is the Atom’s Center Formed? Protons and neutrons are grouped together to form

How is the Atom’s Center Formed? Protons and neutrons are grouped together to form the “center” or ________ of an atom Notice that the electrons are not a part of the nucleus - - + + -

Atomic Structure

Atomic Structure

How are Atoms Described? The Atomic Symbol: • atomic number = ________ • in

How are Atoms Described? The Atomic Symbol: • atomic number = ________ • in a _______ atom, the # of protons = the # of electrons • atomic mass= _________ + _________

 • the number of protons in the nucleus of an atom What is

• the number of protons in the nucleus of an atom What is Atomic Number? - - + ++ - What would be the atomic number of this atom?

What is the Atomic Mass? • the total number of protons and neutrons in

What is the Atomic Mass? • the total number of protons and neutrons in an atom’s nucleus • expressed in Atomic Mass Units (amu) – each proton or neutron has a mass of 1 amu What would be the atomic mass of this atom? + - 3 + ++ 4 3 protons + 4 neutrons = an atomic mass of 7 amu Why did we not account for the electrons when calculating the mass number? - -

Hydrogen (H) Atom • Let’s use the Bohr Model to sketch a hydrogen atom.

Hydrogen (H) Atom • Let’s use the Bohr Model to sketch a hydrogen atom. • notice the one electron in the first orbital P = Atomic # = E=P= N = Atomic Mass – Atomic # =

Oxygen (O) Atom • notice the two electrons in the first orbital/level and the

Oxygen (O) Atom • notice the two electrons in the first orbital/level and the six in the second Bohr Diagram P = Atomic # ____ E=P ____ N = Atomic Mass – Atomic # ____

Sodium (Na) Atom • notice the two electrons in the first orbital/level, eight in

Sodium (Na) Atom • notice the two electrons in the first orbital/level, eight in the second, and one in the third Bohr Diagram P= E= N=