Bell Ringer 11-4-10

1. Which question(s) did you find difficult on the test yesterday?

2. Today you will write about one page of Cornell notes, then you will need a separate sheet of paper for an exit slip.

What we’ve learned so far…

Atoms are made of protons, neutrons and electrons

Protons determine the identity of the element Neutrons determine the isotope Protons and neutrons are located in the nucleus

of the atom

…but what about those electrons?

Electrons in the Atom

November 4, 2010

Rutherford’s model of the atom:Discovered: Atom is mostly

empty space Atom has a small,

positively charged center (nucleus)

Problems: How are electrons

arranged? Why don’t electrons

crash into the nucleus?

How Does a Satellite Stay in Orbit?

Bohr Model Electrons are arranged into

specific orbitals around the nucleus

Electrons have different amounts of energy depending on the orbital they are in

Further away from nucleus = more energy

Closer to nucleus = less energy

Check for Understanding:In your notes: rank the following electrons

from lowest energy to higher energy

1

2

4

3

Energy increases as you move AWAY from the nucleus

4 3 1 2

Electrons can move! Atoms can absorb

energy or emit energy Absorb energy

electrons move to higher orbitals

Release energy electrons move to lower orbitals

Light Energy absorbed/released by atoms can

be in the form of light

Colors of light: ROY G. BIV Red = lower energy Violet = higher energy

Energy Travels in Waves

How are atoms different? Atoms of different elements have orbitals of different

energies. This means they can give off different colors of light!

Atomic emission spectrum: the unique pattern of light emitted by a specific atom

Check for UnderstandingThe atomic emission spectrum of an atom is given

below. Identify which element it is in your notes using the known spectra below.

Hydrogen

Krypton Helium

Xenon

Which element am I???

How do scientists know what stars are made of? Stars are far away and extremely hot, so we

can’t take direct samples of gas! Scientists look at the light given off by the star

hydrogen helium

neon

Spectrum of light from the Sun

Exit SlipFor credit today, copy and complete the following questions

on a separate sheet of paper using your notes:

1. Electrons are arranged in ____________ around the nucleus.

2. How does the energy of orbitals change as you move away from the nucleus?

3. Atoms _____________ energy when electrons move to higher orbitals.

4. Atoms _______________ energy when electrons move to lower orbitals

5. Purple light is __________________ in energy than red light.

6. What is an atomic emission spectrum?