Atomic structure

1. Structure of the Atom

2. Essential Questions
What are the names and symbols of common
elements?
What is the structure of the atom?

3. Review Vocabulary
element: substance with atoms that are all alike

4. New Vocabulary
atom
nucleus
proton
neutron
electron

5. Scientific Shorthand
Scientists have developed their own shorthand for
naming the elements.

6. Subatomic Particles
An element is matter that is composed of only one type of
atom.
An atom is the smallest particle of an element that retains the
element’s properties.
For example, the element iron is composed of only iron atoms
and the element hydrogen is composed of only hydrogen
atoms.

7. Subatomic Particles
Atoms are composed of even smaller particles—subatomic
particles—called protons, neutrons, and electrons, as shown
below.

8. Let’s Explore

9. Let’s Play

10. Atomic number : is the number of the protons in an atom.
Mass number : The sum of the protons and electrons in an
atom.
The atom is neutral when the number of protons equals the
number of electrons.
Positive ion : an atom loses one electron or more.
Negative ion: an atom gains one electron or more.