Physics Chapter 2 Structure of the Atom

4 reasons why the study of atoms is necessary for education and training in radiographic imaging:

1. Interactions in the x-ray tube that produce x-rays 2. Interactions between the x-ray photons and the human body 3. Interactions between the x-ray photons exiting the patient to produce the image interact at the atomic level of the image receptor to generate the final image 4.Electricity

Formula used to determine the maximum amount of electrons a shell can hold:

2n^2 n= shell number (K=1)

Electron shell

A defined energy level at a distance from the nucleus within which electrons orbit; describe a sphere around the nucleus

Binding energy

A force of attraction that holds the nucleus of an atom together and holds electrons in orbit around the nucleus; a measure of the amount of energy necessary to split an atom

Isotope

Elements whose atoms have the same number of protons but a different number of neutrons

All elements are composed of _____________

atoms

The reason for the mass defect is because some mass is converted into ____________________

energy

An atom has defined ______________________ each at different distances from the nucleus

energy levels

Subscript number below chemical symbol

atomic number

Element

A substance that cannot be broken down into simpler parts by ordinary chemical means; the simplest forms of substances that compose matter; made up of one unique type of atom with an unchanging number of protons

Covalent bond

An atomic bond in which an outermost electron from one atom begins to orbit the nucleus of another adjacent atom in addition to its original nucleus; share electrons

These interactions involve attraction to the nucleus of the atom, and the penetrating strength (energy) of the x-ray photon depends on the nuclear binding energy

Bremsstrahlung interactions

_______________________________________ is a rearrangement of atoms

Chemical reaction

___________________________________ is a characteristic of matter, whether it is a subatomic particle, an atom, or a larger object

Electrical charge

The force of attraction between the negatively charged electrons and positively charged protons of the nucleus

Electron binding energy

Isobar

Elements whose atoms have a different number of protons but the same total number of protons and neutrons (atomic mass number)

Isotone

Elements whose atoms have the same number of neutrons but a different number of protons

Isomer

Elements whose atoms have the same number of protons and neutrons but with different amounts of energy within their nuclei ( everything that is all the fundamental particles of the atoms, remains the same)

Molecule

Fixed ratio of each type of constituent atom resulting in a predictable mass; two or more atoms bonded together

2 things electron-binding energy depends on:

How close the electron is to the nucleus How many protons are in the atom (The closer the electron is to the nucleus, the stronger is its binding energy)

How do electrons orbit the nucleus?

In 3 dimension

How are the electrons arranged around the nucleus?

In electron shells labeled K, L, M, N, O, P and so on K being the closest to the nucleus; They fill from the K shell outward with the last shell not necessarily filling completely depending on the stability of the atom

Bonding that is based on the attraction of opposing charges; one of the atoms gives up an electron and the other takes the extra electron the difference in their electrical charge attracts and bonds the two together

Ionic bonding

A way of classifying elements based on number of protons, neutrons, and electrons in each of constituent atoms

Isos

Who discovered the electron? Resulted from the scientific community's fascination with the cathode ray tube which led Dr. Roentgen to his discoveries of x-rays.

Joseph John "J.J" Thomson (Plum Pudding Model)

States that like charges repel each other and opposites attract

Law of Electrostatics

20th-century Danish physicist who refined Rutherford's, bringing us to the theory and model of the atom with which we are most familiar; it is based on the solar system

Niels Bohr

Ionic bond

Occurs when one atom gives up an electron and becomes positively charged and another takes on that electron, acquiring a negative charge and it is the difference in charge that bonds the two together

This rule states that, except for the first (K) shell, a maximum of 8 electrons can exist in the outer most shell of any atom

Octet Rule

What are alpha particles?

Particles that are made up of two protons and 2 neutrons (basically the nucleus of a helium atom) and have a positive charge

Based on mathematics and wave properties, more accurately describes the atom

Quantum Theory

Neutron

Subatomic particle with no electrical charge (neutral)

Electron

Subatomic particle with one unit of negative electrical charge

Proton

Subatomic particle with one unit of positive electrical charge

If a particle strikes the nucleus with the energy equal to the nucleus's binding energy, what could happen?

The atom could break apart

Atom

The basic building block of matter composed of electrons, protons, and neutrons

Nucleus

The central core of an atom made up fundamentally of protons and neutrons

Compound

The combination of elements in definite proportions or bounded together; 2 or more elements; a molecule that contains at least two different elements

What keeps electrons in orbit?

The force of attraction between the negatively charged electrons and positively charged protons (electron-binding energy)

Atomic number

The number of protons an atom contains in its nucleus (Remember that in a stable atom the number of electrons is equal to the number of protons, so this indicates the number of electrons)

Atomic mass number

The number of protons and neutrons an atom has in its nucleus

True or False? Electrons do not all occupy the same orbit at the same distance from the nucleus.

True

An atom that gains an electron and has a net negative electrical charge

anion

Superscript number above chemical symbol

atomic mass number

The bigger the atom the more the ________________________________

binding energy

This energy creates a very strong attraction in the nucleus that overcomes even the natural tendency for like charges to repel

binding energy

7 elements of the periodic table important in radiology:

calcium (Ca), barium (Ba), tungsten (W), aluminum (Al), lead (Pb), oxygen (O), and iodine (I)

An atom that gives up and electron and has a net positive electrical charge

cation

It is the ___________________________ between atoms that allow complex matter (such as living tissue) to exist

chemical bonds

Is an abbreviation of the element

chemical symbol

Particle that is smallest in terms of mass:

electron

The penetrating strength (energy) of the x-ray photon produced depends on the difference in _____________________________ of the electron shells involved

electron binding energies

Atoms in each period of the periodic table have the same number of ______________________________, and they increase as one moves from the top row to the bottom row (the elements become increasingly larger and more complex)

electron shells

Units for electron binding energy:

electron-volts (eV)

In a stable atom the number of __________________________ is equal to the number of protons

electrons

Atoms are mostly made up of ______________________________

empty space

In a covalent bond, an outermost electron from one atom begins to orbit the nucleus of another adjacent atom in addition to its original nucleus creating a __________________________________ as it orbits first one nucleus, then the other

figure eight

The greater the complexity of the atom, the ______________________ the opportunity for interactions to occur

greater

The word atom means____________________________ The Greek term for atom is ________________

indivisible- can't be broken down into anything simpler (atamos)

The electron has very little mass compared with the mass of the nucleus, but each electron moves extremely fast in its orbit, and thus it has significant _______________________________

kinetic energy

All compounds are _________________________, but not all _______________________ are compounds

molecules

If an atom gains an electron it becomes _____________________________

negative and has a negative net charge

If an atom has an equal number of protons and electrons, it is considered _______________________________

neutral; it has no net charge, the positives and negatives are equal and cancel each other out

Both _______________________________ and _______________________________ are key determinates of x-ray production

nuclear binding energy electron binding energy

Protons and neutron are held together in the nucleus by ___________________________________; what is the units for this

nuclear binding energy; MeV

Protons and neutrons are collectively called_______________________

nucleons

Electrons do not all occupy the same _________________________ at the same ______________________________ from the nucleus

orbit distance

In which order are elements arranged on the periodic table?

order of increasing atomic mass

Atoms in each group have the same number of electrons in the ____________________________ shell and increases as one moves from left to right

outermost shell

Another means of classifying elements is according to the ________________________________________

periodic table

The periodic table is organized by ________________________ and _________________________

periods and groups 7 periods arranged as rows 8 groups arranged as columns

Charge of the nucleus of the atom:

positive

If an atom looses an electron it becomes __________________________

positive and has a positive net charge

The __________________ and ________________________ compose the majority of the mass of an atom

protons and neutrons

The atom has a nucleus made up of _________________ and ________________; orbiting the nucleus are ____________________________ in defined energy levels and distances from the nucleus

protons and neutrons electrons

3 fundamental particles that make up the atom:

protons, neutrons, and electrons

Mass of nucleus is always less than the sum of the masses of nucleons that make up the nucleus and this difference in mass is called_______________________________; represents the energy necessary to hold the nucleus together

the mass defect

The quantity of the proton, neutron, and electron is ____________________ to the matter or element it composes

unique