Download Protons are the identity of an atom!

TEKS 8.5A
Atom: The building block of matter; the smallest component of an element that maintains the properties
of that element
Subatomic
Particle
Charge
Size
Location
Positive (+) 1 amu
Nucleus
Neutral
1 amu
Nucleus
Negative
Too small
to count
Outside Nucleus
Electron Cloud
Protons are held inside the
nucleus by a force called the
STRONG force.
Proton
Neutron
Electron
The charge of an atom’s nucleus is
always positive due to the presence of
the prootons.
D. Energy Levels: The rings surrounding the
nucleus that hold the electrons in a Bohr
diagram; also called orbitals, electron shells
An atom with a
charge is called an
ION
B. Neutrons: Neutrally charged subatomic
particles located in the nucleus; add mass to
the atom
E. Electrons: Negatively charged subatomic
particles; Located in the electron cloud; Mass
does not affect the mass of the atom
A. Protons: Positively charged subatomic
particles; located in the nucleus; add mass to the
atom; same as the atomic number; provide
identity of the atom
Protons are the identity of an atom!
A subatomic particle is one of three main parts inside of
an atom- protons, neutrons, and electrons
C. Nucleus: The center of the atom that holds
the mass of the atom; contains protons and
neutrons
Energy
Level
Max # of
Electrons
1st
2
nd
2
8
3rd
8 / 18
When the numbers of
protons and electrons are
equal, the charge of the
atom is NEUTRAL.
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The mass of the atom is
located in the NUCLEUS
Most of the volume of the
atom is Empty Space
Mass – Protons = Neutrons
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I must know/be able to:
-Describe the structure of atoms, including the masses, electrical charges, and locations, of protons
and neutrons in the nucleus and electrons in the electron cloud.
Atoms are the smallest particles of an element. Each element is made
of only one kind of atom. For example, gold is only made of gold atoms
and neon is only made of neon atoms. The overall shape of all atoms is
spherical (like a basketball), but they vary in size.
Each atom has a nucleus located at its center, surrounded by an
electron cloud, which is mostly empty space outside of the nucleus.
The nucleus is very small compared with the overall size of the atom.
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Atoms are made of three different kinds of subatomic particles:
protons, neutrons, and electrons.
All of an atom’s protons and neutrons are tightly packed together in
the atom’s nucleus. The nucleus is held together by the strong nuclear
force, which is stronger than the electromagnetic force that
otherwise would cause like-charged protons to repel one another.
Protons have a positive (+) charge, and each has a mass of one “atomic
mass unit” (amu).
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Neutrons have neutral (sometimes stated as a neutral or zero (Ø)
charge), and each has a mass of 1 amu.
Electrons have a negative (-) charge, and a very tiny mass of 0.005
amu. The mass of electrons are so small that they are ignored when
adding up the mass of the entire atom to state the atom’s atomic
mass.
All of the atom’s electrons are located somewhere in the electron
cloud. It is not possible to know exactly where the electrons of an
atom are located. It is useful to think of electrons as orbiting the
nucleus much as planets orbit the Sun (as shown in the Bohr Model),
though electrons do not really have separate defined orbits.
# Protons = Atomic Number
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Atomic Mass = Protons + Neutrons
BOHR MODEL
ELECTRON CLOUD MODEL
Atoms of a particular element have a set number of protons. For example, every atom of hydrogen has one proton and every atom of gold has 79
protons. The number of protons is called the element’s atomic number.
Atoms that are electrically neutral will have the same number of protons and electrons. If an atom has an electrical charge, it is because it has
more or less electrons than its’ number of protons. In this case, the atom is called an ion.
Not all atoms of the same element will have the same number of electrons and/or neutrons Atoms of an element with different numbers of
neutrons are called isotopes of that element. So, atoms of a particular element can have different atomic masses.
The total number of protons and neutrons in an atom’s nucleus is called the atomic mass of that atom.
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