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An _____ is the smallest particle that has all the properties of an element
Atom
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The center of the atom is called the _____.
Nucleus
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particle accelerators =
atom smashers
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The 3 primary constituents of an atom is the _____, the _____, and the _____.
-
The electron, proton & neutron are considered the _____ _____
fundamental particles
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** The fundamental particles of an atom are the _____. the _____, and the _____.
-
Electrons are very small particles that carry one unit of _____ electric charge
negative
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Because an atomic particle is extremely small, its mass is expressed in _____ _____ _____ for convenience
atomic mass units
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One AMU is equal to _____ the mass of a carbon-12 atom
1/12
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When precision is not necessary,a system of whole numbers called_____ _____ _____ is used.
atomic mass numbers
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The atomic mass number of an electron is _____.
zero
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The nucleus contains particles called _____, of which there are 2 types: protons & neutrons. Both have nearly 2000 times the mass of an electron
nucleons
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The atom is essentially _____ space
empty
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The number of protons determines the ______ ______
chemical elements
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Atoms that have the same number of protons but differ in the number of neutrons are _____; they behave the same way during chemical reactions
isotopes
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Electrons can exist only in certian _____, which represents different _____ ______ ______ or energy levels.
- shells
- electron binding energies
-
In their normal state atoms are electrically neutral; the electric charge on the atom is _____.
zero
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If an atom hhas an extra electron or has had an electron removed, it is said to be _____.
ionized
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Note: Ionization is the removal or addition of an orbital elctron from an atom
-
Note: The atom is essentially empty space
-
The fundamental particles of an atom are the electron, the proton, and the neutron
-
The maximum number of electrons that can exist in each shell increases with the distance of the shell from the _____.
nucleus
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maximum electrons per shell can be calculated by :
2nsquared
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Note: No outer shell can contain more than 8 electrons
-
______ force is the force that keeps an electron in orbit
Centripetal
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Note: The force that keeps an electron in orbit is the centripetal force
-
_____ force is the firce that causes an electron to travel straight and leave the atoom.
Centrifugal
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______ forces make sure the electrons maintain their distance from the nucleus while traveling in a circular path
Centrifugal
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The strength of attachment of an electron to the nucleus is called the _____ _____ _____
electron binding energy
-
The closer an electron is to the nucleus, the more _____ it is bound.
- tightly
- K shell electrons have higher binding energies than L-shell electrons. L more than M and so forth
-
Note: An Atomic Mass Number and the precise mass of an atom are not equal
-
The characterics mass of an element, the _____ _____, is determined by the relative abundance of isotopes and their respective atomic masses
elemental mass
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Note: Isotopes: Atoms that have the same atomic number but different atomic mass numbers are isotopes.
-
Atoms that have the same atomic number but different atomic mass numbers are ______.
isotopes
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Atomic nucleui that have the same atomc number but different atomic mass numbers are _______.
Isobars
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Atoms that have the same number of neutrons but different numbers of protons are _____.
Isotones
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What has the same atomic number and the same atomic mass number
Isomer
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one method of association to help with the is definitions is:
Isotope - same proton
Isobar - same a
Isotone - same neutron
isomer - metastable
-
Note:
Molecule - Atoms of various elements may coombine to form structures called molecules
-
note:
Compund - A chemical compound is any quanity of one type of molecule
-
Note: **
The smallest particle of an element is an atom, the smallest particle of a compund is a molecule.
-
** Some atoms exist in an abnormally excited state characterized by an unstable nucleus.
To reach stability the nucleus spontaneously emits particles and energy and tranforms itself into another atom.
This process is called radioactive disintegration or radioactive decay
-
Atoms of variuos elements may combine to form structures called _______?
Molecules
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A chemical compund is any quanity of one type of molecule is a _____?
Compound
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Hydrogen, oxygen, carbon and nitrogen compose more than _____% of the human body
95%
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Water molecules make up approximately _____% of the human body
80%
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Oxygen & hydrogen combine into water through what?
covalent bonds
-
THe smallest particle of an element is an ____; the smallest particle of a compound is a _____.
-
To reach stability the nucleus spontaneously emits particles and energy and transforms itself into another atom is a process called _____ _____.
- radioactive disintegration
- radioactive decay
-
Any nuclear arrangement is called a _____.
nuclide
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Note: Radioactivity is the emission of particles and energy in order to become stable.
-
Note: Radioactice decay results in emission of alpha particles, beta particles, and usually gamma rays.
-
Note: Half Life- The halflife of a radioisotope is the time required for a quanity of radioactivity to be reduced to one-half its orgiinal value
-
_____ is the emission of particles and energy in order to become stable
Radioactivity
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In addition to stable isotope, many elements have radioactive isotopes or radioisotopes. These mat be artifically produced in machines such as particles accelerators or _____ _____.
nuclear reactors
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Radioisotopes can decay to stability in many ways but two _____ emission and _____ emission, are important here for descriptive purposes.
-
Radioactive matter is not here one day and gone to the next.
Rather, radioisotopes disintegrate into stable isotopes of different elements at a decreasing rate so that the quanity of radioactive material never quite reaches zero
-
The _____ _____ of a radioisotope is the time required for a quanity of radioactivity to be reduced to one-half its orignal value
half life
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All ionizing radiation can be conveniently classified into 2 categories: _____ radiation and _____ radiation.
- particulate
- electromagnetic
-
There are 2 maiin types of particulate radiation: _____ particles and _____ particles.
Both are associated with radioactive decay.
-
The _____ particles is equivelent to a helium nucleus. It contains 2 protons and 2 neutrons. Its mass is approximately 4 amu and it carries 2 units of positive electric charge
alpha
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_____ particles have a is quickly lost and has a short range in matter
alpha
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Positive beta particles are _____.
positrons
-
note: Beta particules differ from apha particles in terms of mass and charge.
They are light particles with an atomic mass number of zero and carry one unit of negative or positive charge. THe only difference between electrons and negative beta particles is their origin.
-
An alpha particle is a helium nucleus that contains ___ protons and ___ neutrons
-
A beta particle is an electron emitted from the nucleus of a _____ atom.
radioactive
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_____ & _____ are forms of electromagnetic ionizing radiation
xrays & gamma rays
-
x-rays & gamma rays are often called ______.
photons
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______ have no mass and no charge
photons
-
_____ travel at the speed of light and are considered energy disturbances in space.
photons
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