Download Atomic Structure - South Kingstown High School

Atomic Structure
A LITTLE REVIEW!
1) What are three particles that make
up the atom?
– Electrons, protons and neutrons
2) What particles make up the center
of the atom?
– Protons and neutrons
3) What is the center of the atom
called?
- The nucleus
4)What does the atomic number of an
element represent?
– the number of protons
AN OXYGEN ATOM HAS 8 PROTONS
IN ITS NUCLEUS
– A HYDROGEN ATOM HAS 1
PROTON IN ITS NUCLEUS
5) What is the atomic number of oxygen?
- SINCE OXYGEN’S NUCLEUS HAS
8 PROTONS ITS ATOMIC # IS 8
The number of protons identify the
atom, the only atom with 8 protons is
oxygen.
electron
e
-1
0
9.11x10-28
proton
p+
+1
1
1.67x10-24
neutron
0
n
0
1
1.67x10-24
6) How do you determine the mass of
each atom?
- the protons plus the neutrons
Mass = protons + neutrons
7) How do you determine the number of
neutrons in each element?
- The mass number minus the protons
equals the neutrons
Mass – protons = neutrons
8)
How do you determine the number
of electrons in each atom?
- Atoms are neutral so the
protons equal the electrons (we
will work with ions later).
5 p+ + 5 e- = 0 charge
5 + (-5) = 0
CHEMICAL COMPOSITION
SHORTHAND
MASS
NUMBER
35
ATOMIC
NUMBER
17
# OF PROTONS
+
# OF NEUTRONS
Cl
NUMBER OF
PROTONS
What are Isotopes?
Atoms that have the same number of
protons but different numbers of
neutrons
EXAMPLE OF AN
ISOTOPE
ATOMIC MASS
Cl
Cl
35
37
17
17
18
NEUTRONS
20 NEUTRONS
ATOMIC NUMBER
Isotopes of Hydrogen
http://education.jlab.org/glossary/isotope.html