Transcript neutrons

Atomic Structure
What is an Atom?
INB Page 123
• Add the Periodic Table of Elements!!
Use your Periodic Table to find the symbol
for each element below (INB page 124) :
1.Hydrogen
6.Boron
2.Sulfur
7.Carbon
3.Fluorine
8.Nitrogen
4.Helium
9.Sodium
5.Silicon
10.Calcium
The answers are …
1.Hydrogen
H
6.Boron
B
2.Sulfur
S
7.Carbon
C
3.Fluorine
F
8.Nitrogen
N
4.Helium
He
9.Sodium
Na
5.Silicon
Si
10.Calcium
Ca
What is an Element?
• Matter that is composed of one type of
ATOM
• Elements are abbreviated in scientific
shorthand – either a letter or a pair of letters
called a symbol.
– Examples: Aluminum – Al, Oxygen – O
Brain pop - Atoms
What is an atom?
• The basic unit of matter!
•Smallest piece of matter that still has the properties
of an element
•Atoms make up everything around you!
• 92 Naturally occurring atoms
• Scientists have created about 25 more
What do atoms consist of?
• Atoms consist of subatomic particles
– The nucleus
• Protons
• Neutrons
– The Electron Cloud
• Electrons
The Nucleus
• The nucleus is the center of the atom.
• The nucleus is made up of protons and
neutrons.
• The nucleus contains MOST of the atom’s mass
Protons
• Subatomic particle with a positive charge +.
• All protons are identical, regardless of the element
in which they are found.
• A proton has a mass of 1 amu (To get an idea of how
small an amu is, imagine the number 6 followed by 23
zeros. That is how many protons it would take to equal a
mass of just one gram.)
• Determines the element (1 P = H, 8 P = O)
Neutrons
• Neutrons are electrically neutral (have no charge).
• Like protons, all neutrons are identical.
• A neutron has slightly more mass than a proton, but
the mass of a neutron is still considered to be 1
amu.
What is a Quark?
• Quarks are believed to be one of the basic building
blocks of matter. Quarks were first discovered in
experiments done at the Stanford Linear
Accelerator Center in the late 1960's and early
1970's.
• Up and Down quarks, join together to form
PROTONS and NEUTRONS.
Atomic Number
• The number of protons in the nucleus of an atom
is the atomic number.
• The atomic number identifies the element.
• All hydrogen atoms – and only hydrogen atoms
– have 1 proton and an atomic number of 1.
• Carbon atoms have 6 protons and an atomic
number of 6.
• How many protons does oxygen, atomic # 8
have? Uranium, atomic number 92? Nitrogen,
atomic number 7?
Electrons
• Electrons have a negative charge.
• Electrons have a mass of 1/1836 amu.
• What is an ION?
– An Ion is an Atom or Molecule that has a
Different Number of Electrons than Protons
• Adding Electrons Creates a NEGATIVE ion
• Subtracting Electrons Creates a POSITIVE ion
BrainPOP - IONS
Electron Cloud
Blurry Area Containing
Electron
Nucleus
Protons + Neutrons