1. Bellringer Write down 5 things you know about atoms.
Use chapter 4 if you need help remembering!

2. Bellringer Use your notes to answer the following
What is all matter made of?
What is the nucleus of an atom?
What two subatomic particles are located in the nucleus of an atom?
Which subatomic particle gives an element its identity?
An element’s atomic number tells the # of ____ in an atom.
What is an isotope? Give an example.

3. Notes: Atoms Matter: Building block of universe.
All matter is composed of atoms.
Energy is not matter (ex. Heat, light, electricity, sound)
History of atom- see timeline p
Atoms can be broken down into subatomic particle

4. Subatomic Particles Protons: Found in the nucleus of atom
Positively charged
Give element its identity
# of protons is equal to the atomic # of each element on periodic table.
ex. Carbon
Silver
Iron

5. Bellringer Use your notes to answer the following.
What is the charge of the nucleus of an atom?
What is the overall charge of an atom?
Fill in the table to the side for protons, neutrons, and electrons:
Mass of Particle
Charge
Location

6. 2. Neutrons: Found in the nucleus of atom No charge (neutral)
# of neutron in an atom can be calculated by formula. Mass # - # of protons
Isotopes: atoms of the same element but with different # of neutrons.
Nucleus: makes up most of the mass of the atom, but takes up very little space.
Contains protons and neutrons
Positively charged

7. Electrons: Found outside the nucleus. Orbits nucleus.
Have very small mass
Have a negative charge
# of electrons is equal to the # of protons.
Overall charge of an atom is neutral. (No charge)

8. Mass #: Mass of nucleus of an atom
Calculated by adding protons + neutrons
Mass # is measured in amu: Atomic mass units.
Atomic Mass: average mass of protons and neutrons including isotopes.
ex.