Name Oscar Gutierrez 8A
Period 5
Atoms and Their Parts (Subatomic Particles)
Substances that contain only one kind of atom are called elements. Some familiar elements are oxygen,
gold, silver, and helium. An atom is the smallest part of an element that can be broken down and still
have the characteristics of that element. All atoms have the same basic structure.
With the exception of hydrogen, all the atoms have three main parts. The parts of an atom are protons,
electrons, and neutrons. A proton is positively charged and is located in the center or nucleus of the
atom, All atoms of the same element have the same number of protons. The number of protons in
the
nucleus is call the atomic number and again, is unique to each element. A different number of protons
would mean you have a different element. Electrons are negatively charged and are located in shells or
orbits spinning around the nucleus. The number of protons and electrons can be equal. This equality is
important SO that the atom is neither positively nor negatively charged. It is said to be neutral. The third
part of an atom is the neutron. Neutrons are neither positive nor negative and are located in the center of
the nucleus of an atom along with the protons. Protons and neutrons are the massive parts of an atom
Their combined masses are called the atomic mass of an element. Electrons are so light that we say they
have essentially no mass.
After reading the above, use the table below to help you understand the basics about protons,
electrons, and neutrons.
Subatomic
Charge
Where Found
Mass
Particle
Yes
No
Positive
Negative
Neutral
Inside Nucleus
Outside Nucleus
Proton
Electron
Neutron
Study the drawings and answer the questions at the bottom of the page.
Legend:
Proton
+
Neutron
Electron
Atom A
Atom B
1. How many protons are in atom A?
atom B?
8
2. How many neutrons are in atom A?
0
atom B? 10
3. How many electrons are in atom A?
1
atom B?
8
4. What is the atomic mass of atom A?
1
atom B? 18
5. What is the atomic number of atom A?
1
atom B?
8
