1. Ch. 3.1 Introduction to Atoms
Atoms Song (3:49)

2. Introduction to Atoms
I. The tiny objects that make up all matter are _atoms_.
What is an Atom? (5:52)

3. II. Structure of An Atom A. Atoms are made up of small particles
called _protons_,
_neutrons_ and _electrons_.
B. Particles in Atoms
1. Nucleus = very small _center_ _core_
2. Protons = have a _positive_ electric charge
3. Neutrons = have _no_ charge
4. Electrons = have a _negative_ electric charge
A Boy and his Atom (1:33)

4. Atoms
5. The _positive_ charge from the protons equals the _negative_ charge from the electrons.
6. The charges _balance_ or make atoms _neutral_.
Brain Pop Atoms

5. C. A Cloud of Electrons 1. Electrons move _around_ the nucleus.
2. Electrons with _lower_ energy move closer to the nucleus.
3. Most of the atom’s _volume_ is the space in which the _electrons_ move.

6. D. Comparing D. Comparing Particle Masses
1. It takes _2,000_ electrons to _equal_ the mass of just _one_ proton.
2. The mass of a proton _equals_ the mass of a neutron.
3. Units of measure for atoms are _atomic_ _mass_ _units_ (amu)

7. E. Describe Models of Atoms
Dalton’s Model = Each element is made of atoms that are all alike. Atoms are like tiny
solid balls.
Atoms/Scientists (3:28)

8. Models
Bohr Model = Electrons move in specific layers or shells, not randomly. Atoms absorb or give off energy when the electrons move from one shell to another.
Brain Pop Atomic Model

9. III. Models and Atoms
A. An element can be identified by the number of _protons_ in the _nucleus_ of its atoms.
B. Atomic number = number of
_protons _ in its nucleus

10. Models and Atoms
C. Isotopes = atoms with _same_ number of protons but _different_ number of neutrons
D. Mass Number = sum of the _protons_ and _neutrons_ in the nucleus
Brain Pop Isotopes

11. IV. Modeling Atoms
A. Atoms are hard to study because they are _amazingly_ _small_.
B. Scientists create _models_ to study atoms because they are so small.

12. Models
C. Model = a _diagram_, _mental_ _picture_, _mathmatical_ _statement_ or _object_ to explain ideas about the natural world.
D. Models are used to _make_
and _test_ predictions.
E. The modern atomic model explains
_why most elements react with other elements, while a few elements hardly react at all_.
Atoms