chapter 6 Flashcards
Who was the primary contributor to the periodic table?
Dimitri Mendeleev (1837-1907) - chemist
Who was the secondary contributor to the periodic table?
Henry Moseley (1887-1915) - physicist
What contributions did Mendeleev make to the periodic table?
-elements were ordered by atomic mass
-saw repeating patterns of properties
-used pattern to predict undiscovered properties
-when atomic mass order did not fit other properties, he re-ordered by other properties
What contributions did Moseley make to the periodic table?
-realized that the atomic number was more meaningful
-allowed for more accurate positioning of elements on the periodic table
What was the periodic law?
when the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically
______ summarize behavior
laws
______ explains behavior
theories
What was the importance of the periodic law?
it allows us to predict what the properties of an element will be based on its position on the table
What are quantum mechanics?
its a theory that explains why the periodic trends in the properties exists (allows us to make predictions)
Who was attributed to the periodic law?
Mendeleev
What is the atomic radii property?
the physical size of an atom or ion (an estimated size)
What is the ionization energy property?
the energy it takes to remove or expel an electron in the gas phases (form a cation)
What is the electron affinity property?
the energy it takes to add an electron in the gas phases (form an anion)
What happens to a elements radius as you go down the group? (up to down)
increase
What happens to a element radius as you go across the period/row? (left to right)
decreases
How does the radius decrease?
when electrons add to the same shell, there is pull or attraction that causes all the electrons to be closer to the nucleus; therefore, adding electrons causes the atomic radius to decrease
What happens to cations in relation to the atomic radii property?
they lose electrons (positive charge) and decrease in atomic size (smaller
What happens to anions in relation to the atomic radii property?
they gain electrons (negative charge) and increase in atomic size (larger)
How do we make anions?
when an atom gains electrons (electron affinity)
How do we make cations?
When an atom loses electrons (ionization energy)
IE is endothermic T/F
true
What happens to a elements ionization energy as you go down the group? (up to down)
decreases
What happens to a elements ionization energy as you go across the period/row? (left to right)
increases
electron affinity is exothermic- what does that mean
it’s usually a negative number
What happens to a elements electron affinity as you go across the period/row? (left to right)
increases
What are the three different types of thermal energy exchange?
endothermic, exothermic, enthalpy
What are the two different types of energy from electrons exchange?
electricity, fireworks
Why is direct observation of electrons within an atom impossible?
due to electrons being so small that they are unaffected by light
Electrons behavior determines much of the behavior of ______
atoms
What is the definition of light?
the form of electromagnetic radiation; type of energy in oscillating electric and magnetic fields
What is the electric field?
a region where an electrically charged particle experiences a force
What is a magnetic field?
a region where a magnetized particles experience a force
What is wavelength?
the distance between adjacent crests or troughs in a wave; creates different colors
What is frequency?
the number of complete wave passing during a point in a given period of time
What makes amplitude different from wavelength?
amplitude changes the brightness
What is spectra?
when atoms or molecules absorb energy, that energy is often released as energy (light)
What is emission spectra?
when that emitted light is passed through a prism, a pattern of light is seen that is unique to that type of atom or molecule; two types
what are the two types of emission spectra?
continuous, line
What is an orbital?
a probability distribution map of regions within an atom where an electron is likely to be found
the _____ the principle quantum number, the ____ the orbital shell and the _____ the energy level
higher; larger; higher
What are the four different shapes or orbital subshells?
s-orbital, p-orbital, d-orbital, f-orbital
What is paramagnetism?
when some atoms and ions will align (weak magnetism)
What is ferromagnetism?
spins of unpaired electrons align in the same direction of the magnetic field
How are ionic bonds classified?
a transfer of electrons of metals and nonmetals, 1.7+
How are covalent bonds classified?
the sharing of electrons between nonmetals
How are metallic bonds classified?
the pooling of electrons between metals
What are valence electrons?
electrons in the outermost shell; shared in covalent compounds
What ions are the easiest to remove?
valence electrons
What is polarity?
unequal sharing of electrons
What is electronegativity?
ability of an atom to attract electrons
What is a resonance structure in chemistry?
Resonance structures are a group of two or more Lewis structures that represent ‘ electronic bonding
What is the Heisenberg Uncertainty Principle?
it is impossible to determine simultaneously both the position and velocity of an electron or any other particle
What is the Pauli Exclusion Principle?
no two electrons in the same atom can have the same set of four quantum numbers
What is Hund’s rule?
every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.
What is the octet rule?
Atoms tend to gain, lose or share electrons in order to have a full set of valance electrons.
What is formal charge?
the charge associated with each bonded atom if all the electrons are shared equally
the _shorter___ the bond, the ____ the bond
stronger
what does nonpolar mean?
equal sharing of electrons
What does polar mean?
unequal sharing of electrons
What are columbic forces?
the attraction between a nucleus and an electron increases; with increasing magnitude of nuclear charge or atomic number
What are the types of electron geometry?
Linear, Trigonal planar, Tetrahedral, Trigonal bipyromidal, octohedral
What are the types of molecular geometry?
bent, square pyramidal, square planar, seesaw, T-shape, Linear
