Study for the quiz! 1. What did Rutherford show with his Gold Foil Experiment? 2. What is the name of Group 7/17? 3. What reacts with the Noble Gasses? 4. A member of Group 1 joins with a member of Group 7 to form a ________ 5. How many electrons are in the outer layer of Oxygen?

Practical vs. Applied Science Practical Science – research of atoms Practical Science – research of atoms Applied Science – application of what was being learned. Was happening all along with the development of the Atomic Theory. Applied Science – application of what was being learned. Was happening all along with the development of the Atomic Theory.

The Nucleus It’s where the protons and neutrons live. It’s where the protons and neutrons live.

Weight? (Atomic Mass Unit) Weight? (Atomic Mass Unit) Charge? Charge? How can we tell how many are in an atom? How can we tell how many are in an atom? What element’s nucleus is 1 proton? What element’s nucleus is 1 proton?

Weight? Weight? Charge? Charge? Where located? Where located?

Weight? Weight? Charge? Charge? Where located? Where located? How can we tell how many in an atom? How can we tell how many in an atom? But when, Mr. Brady, will I encounter electrons? But when, Mr. Brady, will I encounter electrons?

Positives & Negatives What do unlike charges do? Attract What do unlike charges do? Attract What do like charges do? Repel. What do like charges do? Repel. What does this mean for protons and electrons? What does this mean for protons and electrons?

Add or subtract electrons – you have an ion. Add or subtract electrons – you have an ion. Definition: an atom where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative charge. Definition: an atom where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative charge. Anion – more electrons than protons, negative charge Anion – more electrons than protons, negative charge Cation – more protons than electrons, positive charge Cation – more protons than electrons, positive charge

Add a neutron to a nucleus – do you still have the same element? Add a neutron to a nucleus – do you still have the same element? You have an isotope. You have an isotope. Isotope: the same element as before, but with a different number of neutrons. Isotope: the same element as before, but with a different number of neutrons. Usually named by their mass number Usually named by their mass number

Isotopes – add neutrons Isotopes – add neutrons Ions – add or subtract electrons Ions – add or subtract electrons Proton Proton Neutron Neutron Electron Electron Atomic Mass Atomic Mass Atomic Number Atomic Number

They aren’t in specific “orbits” – they’re in a “cloud” – and electron cloud, which is better represented like this: They aren’t in specific “orbits” – they’re in a “cloud” – and electron cloud, which is better represented like this: The probable location of the electrons

Still, we say that electrons spin around the nucleus in certain energy levels, or shells. Still, we say that electrons spin around the nucleus in certain energy levels, or shells. The electrons around a nucleus can be found in one of seven shells. Each shell can hold a set number of electrons. The electrons around a nucleus can be found in one of seven shells. Each shell can hold a set number of electrons. Each shell can hold 2n 2 electrons, where n is the shell number. Each shell can hold 2n 2 electrons, where n is the shell number.

Oxygen – 8 electrons. Where are they? Oxygen – 8 electrons. Where are they? Shell 1 – 2(1) 2 = 2 electrons Shell 1 – 2(1) 2 = 2 electrons Shell 2 – (can hold 8) = 6 electrons Shell 2 – (can hold 8) = 6 electrons Electrons fill shells before moving on to the next Electrons fill shells before moving on to the next

How many electrons? 6 How many electrons? 6 Where are the electrons located? Where are the electrons located? 2 in shell 1, 4 in shell 2.

Sodium11p Carbon 6e Hydrogen 1e Argon 18e Oxygen 8e Helium 2e Neon 10e Chlorine 17e

Atoms want their shells full. Atoms want their shells full. Outermost shell is called the valence shell Outermost shell is called the valence shell Electrons in the outermost shell are called valence electrons Electrons in the outermost shell are called valence electrons These are where the action is at. These are where the action is at.

The further out the shells are, the higher the energy state The further out the shells are, the higher the energy state There are seven shells – how many periods are there in the Periodic Table? There are seven shells – how many periods are there in the Periodic Table?

That is to say… Shells correspond to the Periods of the Periodic Table. Shells correspond to the Periods of the Periodic Table.

Atoms want their valence shells to be full, WITH 8 ELECTRONS. Full shells = lower energy state. Atoms want their valence shells to be full, WITH 8 ELECTRONS. Full shells = lower energy state. The closer they are to full, the more reactive the atom is. The closer they are to full, the more reactive the atom is. Think about this in terms of the Groups. Think about this in terms of the Groups.

Those that have more, want more – the halogens & neighbors. Those that have more, want more – the halogens & neighbors. Those that have the least, give the most – the alkalis and neighbors. Those that have the least, give the most – the alkalis and neighbors. Halogens – just need one Halogens – just need one Alkalis – just have one Alkalis – just have one

Valence electrons – where it’s at. Valence electrons – where it’s at. Periods – correspond to the shells Periods – correspond to the shells For Groups 1-8 (skipping Transition Metals), the # of valence electrons = Group # in Periodic Table For Groups 1-8 (skipping Transition Metals), the # of valence electrons = Group # in Periodic Table By Groups – see the same number of valence electrons. Elements in Groups share reactivity, remember? By Groups – see the same number of valence electrons. Elements in Groups share reactivity, remember?

Arts & Crafts - Build a Bohr Model. Build a Bohr Model. Select an element Select an element Pick out your parts Pick out your parts Format it correctly, and place everything in the right spot. Format it correctly, and place everything in the right spot.