M1U2 Flashcards
Electrons are very small particles that carry â unit of negative electric charge.
one
Electrons can be pictured as revolving about the nucleus in â orbits, just as the planets in our solar system revolve around the Sun.
precisely fixed
Unit of measure used to identify the size of an atomic particle that is so small.
Atomic mass units (amu)
One atomic mass unit is equal to (1) of the mass of a (2).
- one-twelfth
- carbon-12 atom
A system of whole number that is used when precision is not necessary.
Atomic mass numbers
Equation for atomic mass
A= Protons + neutrons
Equation for neutrons
n= A-Z
They are particles contained in the nucleus of an atom
Nucleons
Types of nucleon
Protons
Neutrons
The primary difference between a proton and a neutron
Their electric charge
p= one unit of positive electric charge;
n= no charge; electrically neutral
Essentially empty space
Atom
In what model does the electrons circle the nucleus in the same way that planets
orbit the Sun?
Bohr model of the atom
The circles where the electrons orbit
Energy levels/ Shells/ Orbits
Electrons in the (1) have higher (2) since it requires more effort to (3) the electron a greater (4) from the nucleus.
- outermost circles
- energy
- pull
- distance
How are energy levels denoted?
The energy levels are numbered as 1, 2, 3, etc. or instead of numbers, we use the letters K, L, M, etc.
The value of n is sometimes called the â
principal quantum number
Each â can only hold a certain number of electrons.
energy level
How many electrons can each shells hold? (K-O)
K: 2
L: 8
M: 18
N: 32
O: 50
As the â increases, so does the number of electrons that can fit into the shell.
energy level
Formula to predict the maximum number of electrons that can fit into an energy level
Max # of electrons = 2đ^2
Within each energy level are (1). They are labeled (2)
- sublevels
- s, p, d, f
What sublevels do the first-fourth energy levels contain?
First energy level: s sublevel
Second energy level: s and p sublevels
Third energy level: s, p, and d sublevels
Fourth energy level: s, p, d, and f sublevels
The number of sublevels in an energy level is equal to the number of the â
energy level
Within each sublevel, there are â.
orbitals
Maximum number of electrons that can occupy an orbital
2 electrons
This is the final location where electrons reside
Orbitals
Number of orbitals each sublevel has
s sublevel: 1 orbital
p sublevel: 3 orbitals
d sublevel: 5 orbitals
f sublevel: 7 orbitals
Summarize the terms related to where the electrons orbit
Electrons orbit the nucleus in circles called energy levels (n). Inside the energy levels are sublevels (s,p,d,f). Inside the sublevels are orbitals.
Electrons fill the orbitals according to a pattern called â
Electron configuration
Rules for filling the orbitals
- Start with the lowest energy level, ân.â
- Choose the lowest sublevel s, p, d, or f.
- Fill the orbital with a max of 2 electrons
- Before a second electron can be placed in any orbital, all the sublevels must contain at least one electron.
Primary constituent of tissue
Interaction b/n an x-ray and a carbon atom
Ionized atom and the released electron
Ion pair
Removal of an orbital electron from an atom
Ionization
Required energy for ionization
Approximately 34 eV
Determines the chemical element and the behavior of an atom
Number of protons
The force that keeps an electron in orbit
Centripetal force
What is the Centripetal force called?
center-seeking force
The force that causes an electron to travel straight and leave the atom
Centrifugal Force
What is the Centrifugal Force called?
flying-out-from-the-center force
The strength of the attachment of an electron to the nucleus
Electron Binding Energy
Has a symbol of đžb
Electron Binding Energy
Atomic Nomenclatures
- Atomic Nomenclature
- Number & Arrangement of Electrons
- Atomic number
- Atomic Mass Number
- Protocol for Representing
Elements in a Molecule
The alphabetic abbreviations of an element
Atomic Nomenclature
Determines the chemical properties of an element
Number & Arrangement of Electrons
It is equal to the number of protons
Atomic number (Z)
Protocol for Representing
Elements in a Molecule
Upper Left: atomic mass (A)
Lower Left: atomic number (Z)
Upper Right: valence state (+/-)
Lower Right: number of atoms/molecules
The atomic number & the precise â of an atom are not equal
mass
The group of atoms of various
elements
Molecules
The smallest unit of a compound
Molecules
90% of the human body
CHON (C-6, H-1, O-8, N-7) = Carbon, Hydrogen, Oxygen, Nitrogen
Any quantity of one type of molecule
Chemical Compound
Example of a Chemical Compound
NaCl (Sodium Chloride) â common table salt
The chemical union between atoms formed by sharing one or more pairs of electrons
Covalent Bond
Example of a Covalent Bond
H2O
The bonding that occurs because of an electrostatic force between ions
Ionic Bond
Example of Ionic Bond
NaCl
Sodium bicarbonate (NaHCO3)-Baking soda
Primary constituents of the x-ray tube target
Tungsten (W-74)
Molybdenum (Mo-42)
Radiographic & fluoroscopic contrast agents
Barium (Ba-56
Iodine (I-53)
Important component of human tissue
Carbon (C-6)
The amount of energy (34 keV) necessary to ionize tissue atoms
Ionization Potential
How much energy is necessary to ionize tissue atoms
34 keV
Difference between an atom and molecule
Atom: smallest particle of an element
Molecule: smallest particle of a compound
