Proton:(p+)
-positively charged particle, equal
in strength to the e-mass negligible but much larger
than electrons 1p+ = 2000 e-
Neutron:(n)
-neutral particle
-slightly more mass than the proton
made up of
made up of
Atomic Theory of Matter: (John Dalton, 1766-1844)
1. Each element is composed of extremely small particles called atoms
2. All atoms of a given element are identical, but differ from any other
element
3. Atoms are neither created or destroyed in any chemical reaction
4. A given compound always has the same relative numbers and kinds
of atoms
Nucleus:
-positively charged center
-contains most of the mass
-made up of protons and neutrons
Electrons:(e-)
-negatively charged particles
-mass negligible
Atomic Number:
-number of protons in a nucleus
7
orbiting the neucleus
N
center of the atom
where electrons are located
Electron Cloud:
-a cloud that surrounds the nucleus
-region where an electron is likely to be at any time
-the farther away from the nucleus an electron is, the
higher the energy level.
The Atom:
-basic building blocks of matter
-smallest particle of an element that retains the
chemical identity of that element
-mostly empty space
-If an atom is the size of a football stadium, the
nucleus would be a dime in the middle of the
field. The electron would be smaller than the eye
on Franklin Roosevelt on the dime.
measurement
of the atom
Atomic Mass Unit (AMU):
mass of both p+ and n is 1 AMU and the
mass of e- is 0 AMU
Arbitrary standard used; carbon 12
So 1 AMU = 1/12 mass of carbon 12 atoms
= 1.66 x10-24
loses/gains
electrons
Ion:
when an atom gains or loses eIon Charge:
# of p+ - # of e-
Nitrogen
14.01
(Atomic) Mass Number:
-sum of the number of protons and
neutrons in the nucleus of an atom
Number of Neutrons:
Mass Number - Atomic Number
loses/gains
neutrons
Isotopes:
-atoms of the same element that have the same number
of protons but a different numbers of neutrons
-Element is determined by the number of protons