Download Document

The Atom
• the smallest unit of an
element
• protons and neutrons in
nucleus
• surrounded by one or >
shells of electrons
• neutral atoms: #
protons = # electrons
Protons
Pro=For=Positive
• a positively charged
particle in the nucleus
of an atom
• protons + neutrons =
atomic mass
• # protons = atomic #
• Nucleus
P+
Neutron
neutral=neither positive nor negative
• Nucleus
P+ N
• a neutrally charged
particle in the nucleus
of an atom
• can be > neutrons than
protons
• protons + neutrons =
atomic mass
12C
or C-12
14C or C-14
Carbon has 6 protons.
How many neutrons?
Electron
electricity-zaps-ouch-negative
shell outside
nucleus
• a negatively charged
particle surrounding an
nucleus of an atom
• neutral atom: electrons
= protons
e-
Atomic Number, Atomic Mass, P+, N, e•
•
•
•
•
•
•
•
•
•
What determines the atomic number
The number of protons in an atom
What determines atomic mass
The number of protons and neutrons
Where is the proton found and what is its charge?
Nucleus, positive
Where is the neutron found and what is its charge?
Nucleus, neutral
Where is the electron, and what is its charge?
Around nucleus, negative
6 protons
6 neutrons
6 electrons
6 protons
7 neutrons
6 electrons
6 protons
8 neutrons
6 electrons
Isotopes: an atom of an element that can
have different numbers of neutrons
Neutrons, > neutrons, even > neutrons but
still same element
Ions
All About Electrons Coming and Going
• a charged particle that has either more or fewer
electrons than protons
• positive or negative depending on whether electrons
eare gained or lost
e- Anion
A Negative Ion
• More electrons
than protons
• Electrons gained
Cation
Carry away electron
• More protons
than electrons
• Electrons lost
Ion Examples
Sodium and Fluorine
Na
Na+
Lose e-, go positive
F
FGain e-, go negative
Isotopes and Ions
• What is an isotope?
• An atom of an element that can have different
numbers of neutrons.
• What is an ion?
• A charged particle that has either more or
fewer electrons than protons because
electrons have been gained or lost.
Review Website
• Review vocabulary at
quizlet.com.
• Search mrpolinski to
find my sets.