Transcript Parts of an Atom - Queen Anne's County Public School District

Parts of an Atom
First off, what is an atom?
 Atoms
are the smallest parts to
which an element can be divided
yet still be that element.
 Atoms are the building blocks of all
matter.
How small is an atom?

An atom is so small that a penny
contains about 2 x 1022 or
20,000,000,000,000,000,000,000
atoms!!!
But there’s more…

Atoms consist of even smaller particles.
These include:
– Protons
– Neutrons
– Electrons
Parts of an Atom
The protons and
neutrons make up
the center or
nucleus.
The Nucleus
 The
center of an atom
 Small, dense (packed tightly)
 Contains protons and neutrons:
most of the atom’s mass
 So dense, if it were the size of a
grape, it would weigh over 9 million
tons!
Protons
Located in the
nucleus
 Positive charge (+)
 Mass of 1 atomic
mass unit (amu)

protons = positive
Neutrons
 Located
in the
nucleus
 Have no charge
- neutral
 Mass of 1 amu
neutrons = neutral
Electrons
Found outside of the nucleus in electron
clouds
– (think of rings around a target)
 Negatively charged (-)
 Mass of almost zero
 Number of electrons equals the numbers
of protons to cancel out the charges
– (think of -1+1=0)
electrons = negative

Review: Parts of an Atom
Parts
Charge
Location
Mass
Proton
Positive (+)
Nucleus
1 amu
Neutron
No charge
Nucleus
1 amu
Electron
Negative (-)
Electron
Clouds
Almost zero