bell ringer think back to last class & the history of the atom! without using your notes match...
TRANSCRIPT
Bell RingerTHINK BACK TO LAST CLASS & The History of the Atom! WITHOUT using your notes match the scientist to
the correct statement that describes his work.
Ernest Rutherford J.J. Thomson Schrodinger & Heisenberg
John Dalton Democritus Niels Bohr 1. _______________________________ proposed that all matter is made up of tiny particles called atoms (from the word that means "indivisible.") 2. _______________________________ suggested that electrons travel in well-defined paths. 3. _______________________________ discovered that atoms have electrons and thought that they were embedded in positively charged material. 4. _______________________________ proposed that matter is composed of atoms and the atoms of an element are identical. His Atomic Theory suggested that atoms can be thought of as being much like a small uniformly solid ball. 5. _______________________________ concluded that there is a small, dense, positively charged nucleus. 6. ______________________________ proposed that electrons travel in electron clouds.
Unit 3: Chemistry. Introduction to Atoms.
How big is an atom?
On average the diameter is
0.00000003 cm!
Unit 3: Chemistry. Introduction to Atoms.
LET’S WATCH THE TED ED VIDEO!https://www.youtube.com/watch?v=yQP4UJhNn0I
Unit 3: Chemistry. Introduction to Atoms.
What is inside an atom?
Electrons: are negatively charged particles found
in electron clouds outside the nucleus.
The Nucleus: is the small, dense,
positively charged center of the atom. It contains most of the
atom’s mass.
The diameter of the nucleus is 1/100,000 the diameter of
the atom.
Protons: are positively charged particles in the
nucleus if the atom.
Neutrons: are particles in the nucleus of an
atom that have no charge.
Unit 3: Chemistry. Introduction to Atoms.
Atomic mass unit (amu): the SI unit used to express the masses of particles in
atoms
Neutron
Charge: none
Mass: 1 amu
Location: nucleus
Electron
Charge: negative
Mass: almost zero
Location: electron clouds
Proton
Charge: positive
Mass: 1 amu
Location: nucleus
Unit 3: Chemistry. Introduction to Atoms.
Fun Fact: If it were possible to have a nucleus the volume of an average grape, that nucleus
would have a mass greater than 9 MILLION TONS!
Unit 3: Chemistry. Introduction to Atoms.
The atom is neutral when there are equal number protons and electrons.
If the number of protons and electrons are not
equal, the atoms becomes a charged
particle called an ion.
Unit 3: Chemistry. Introduction to Atoms.
Stop and think…1)What particles form the
nucleus?2)Explain why atoms are
neutral.
Atomic number: the number of protons in the nucleus.
This # determines what type of element it is!
Unit 3: Chemistry. Introduction to Atoms.
Atomic mass: the sum of the protons and neutrons in an
atom
Unit 3: Chemistry. Introduction to Atoms.
Isotopes are atoms that have
the same number of protons but have different
number of neutrons.
Unit 3: Chemistry. Introduction to Atoms.
Atomic Mass-Number of protonsNumber of neutrons
_____ neutrons _____ neutrons _____ neutrons
Calculate the number of neutrons for these carbon isotopes!!!