The first group of people who recorded reference to the investigation of the structure of matter. They also thought that matter was composed of four substances : earth,water, air and fire
Greek - called greek atoms
It is the building block of the radiogrpaher’s understanding of the interaction between ionizing radiation and matter
Atom
What are the four basic essences when the combination of the four substances happen according to greek atom?
Wet
Dry
Hot
Cold
Where was the word atom originated?
Greek
atom in scientific explanation
Indivisible
A(not) + temon (cut) = cannot be cut (smallest)
How many substances or elements have been identified today? How many are naturally occuring and artificially producedL
112
92 - naturally occuring
20 - artificially produced
It is the smallest particle of matter that has the properties of an element
Atom
Particles that are much smaller that the atom
Subatomic particles
He showed that the elements should be classified according to integral value of the atomic mass
John Dalton, 1808
What is John Dalton’s physical combination of one type of atom with another called?
Eye-and-hook affair
According to him an element was composed of identical atoms that reacted the same way chemically. E.g. All oxygen atoms were alike
John Dalton
Eye-and-hook affair is explained by
John Dalton
Who invented the first periodic table of elements?
Dmitri Mendeleev
He showed that if the elements were arrenged in order of increasing atomic mass, a periodic reptition of similar chemical properties occured
Dmitri Mendeleev
During the time of Dmitri Mendeleev, how many elements had beed identified?
65
The subscript in each of the element in the periodic table is the _______ ________
Atomic number
True/False - all elements in the same group react chemically in a different fashion and have similar phisycal properties.
False
The superscript in each element in the periodic table is the _________ ____
Elemental mass
What do we call the group I in the periodic table of elements?
Alkali metals
The group VII in the periodic table of elements are called _______
Halogens
They are soft metals that combine readily with oxygen and react violently with water
Alkali metals - Group I
They are the group in the periodic table of elements which are easily vaporized and combine with metals to form water-soluble salts
Group VII - halogens
The group VIII elements in the periodic table is called
Noble gases
The group in the periodic table that are highly resistant to reaction with other metals
Noble gases - Group VIII
He described the atom as looking someting like a plum pudding
J.J Thomson
He concluded that electrons were integral part of all atoms
J.J. Thomson
The plum in the plum pudding theory by J.J Thomson represents the
Negative electric charges - electrons
The pudding in the plum pudding theory of J.J. Thomson is the
Shapeless mass of uniform positive electrification
True/false - the number of electrons was thought to be equal to the quantity of postitive electrification because the atom was known to be electrically neutral
True
He introduced the nuclear model of atom and disproved the Thomson’s model of atom
Ernest Rutherford, 1911
This model of atom described the atom as containing small, dense, positively charged center surrounded by a negative cloud of electrons
Nuclear model of atom
He states that “the number of electrons was thought to equal the quantity of postitive electrification because the atom was known to be electrically neutral”
J.J. Thomson
Who called the center of the atom the nucleus?
Ernest Rutherford
He improved Rutherford’s description of the atom and His model was a miniature solar system
Niels Bohr, 1913
The model of atom in which it describes that the electrons revolved about the nucleus in prescribed orbits of energy levels
Miniature solar system model
The equipment used to mapped and identify the structure of the atomic nucleus
High-energy particle accelerators or atom smashers
The atomic model after Bohr’s model, “atoms contains a small,dense, positively charged nucleus surruonded by negatively charged electrons that revolve in fixed, well-defined orbits about the nucleus”
Quantum Chromodynamics (QCD)
The nucleus is also called
Nucleons
The nucleons are composes of
Proton and neutron
Protons and neutrons are held together by
Gluons
What are the fundamental particles or the three primary constituents of an atom?
Electron
Proton
Neutron
The atomic model in which the sun is nucleus and the planets are the electrons
Miniature solar system model
A very small particles that carry one unit of negative electric charge
Electron
What is the mass of an electron?
9.1 x 10^-11 kg
One atomic mass unit is equal to
One half the mass of a carbon 12 atom
The electron mass is equal to how many amu?
0.000549 amu
Atomic mass number of electron is
Zero
The mass of a proton is
1.673 x 10^-27 kg
The atomic mass number of proton and neutron is
One
The mass of the neutron is
1.675 x 10^-27 kg
It carries one unit of postive electric charge
Proton
A fundamental particle that is very small but contains nearly all the mass of the atom
Neutron
It carries no charge; it is electricall neutral
Neutron
The atom is essentially ______ ______
Empty space
electron orbits are grouped into different _____
Shells
It determines the chemical behavior of an atom
Number of protons
The chemical element is determined by the
Number of protons
Atoms that have the same number of protons but differ in the number of electrons
Isotopes
Electrons can exist only in certain shells, which represent different _______ ________ ________
Electron binding energies
Electron binding energies are also called
Energy levels
The elecron orbital shells are given the codes of
K,L,M,N and so forth , it represent the relative binding energies of electrons from closest to the nucleus to farthest from nucleus
True/False - the closer and electron is to the nucleus, the lesser is its binding energy
False
In their normal state, atoms are electrically _______; the electric charge on the atom is zero.
Neutral
The most complex naturally occuring element
Uranimum
True/false - the total number of electrons in the orbital shells is equal to the number of protons in the nucleus
True
If an atom has an extra electron or has had an electron removed, it is said to be _________
Ionized
True/False - am ionized atom is not electrically neutral but carries a charge equal in magnitude to the difference between the numbers of eletrons and protons
True
True/False - atoms can be ionized by the addition or subtraction of protons/false
False - cannot -
Proton - because they are bound very strongly together
Neutron - because they are electrically neutral
After the electron is removed from an atom due to ionization the remaining atom is called a
Positive ion - contains one more positive charge than negative charge
How many eV is required to remove an electron from an atom in a tissue?
34 eV
It is the removal of an orbital electron from an atom
Ionization
True/False - in all except the ligthest atoms, the number of neutrons is always greater than the number of protons
True
Large atom = abundance of neutrons over protons
True/False - the maximum number of electrons that can exist in each shell decreases with the distance of the shell from the nucleus
False - increases
The formula for calculating the maximum electrons per shell
2n^2
N = shell number or principal quantum number
The number of electrons in the outermost shell of an atom is equal to its ______ in the periodic table
Group -
it is also determines the valence of an atom
The number of outermost electrons shell of an atom is equal to ______ in the periodic table
Period
True/False - no outer shell can contain more than eight electrons
True
The atoms associated with the phenomenon of that instead adding electrons to next outer shell, electrons are added to an inner shell
Transitional elements
It indicates the relative energy by which the electron is attached to the nucleus
Electron shells
True/false - centripetal force is based on the basic law of electricty that sates that “opposite charges attract one another and like charges repel”
True
The force that keeps an electron in orbit is the
Centripetal force/center-seeking force
The strength of attachment of an electron to nucleus i ps called the _______ _______ _______
Electron binding energy
The force that balances with centripetal force and maintain the distance of the electrons from the nucleus while traveling in a circular or elliptical path
Centrifugal force or flying-put-from-the-center force
True/false - the closer an electron is to the nucleus, the more tightlty it is bound. So therefore K-shell have higher binding energies than other shell
True
True/False - the greater the total number of electrons in an atom, the more tightly each is bound
True
