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Definition
a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire |
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Definition
able to be hammered or pressed permanently out of shape without breaking or cracking. |
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Term
What was John Newland known for |
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Definition
First organization scheme for the elements |
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What was Mendeleev known for |
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Definition
Created first periodic table |
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Term
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Definition
There is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number |
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What are Representative Elements |
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Definition
Elements in the S & P blocks of the periodic table.
contain 3 main groups, the alkali metals, the alkaline earth metals, and the post-transitional metals.
An element whose highest occupied s or p sublevels are partially filled.
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Term
What are Transition Elements |
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Definition
those elements having a partially filled d or f subshell in any common oxidation state.
Elements located in the D block of the periodic table
The 2B elements zinc, cadmium and mercury do not strictly meet the defining properties, but are usually included with the transition elements because of their similar properties. The f-block transition elements are sometimes known as "inner transition elements". The first row of them is called the lanthanides or rare earths. The second row consists of the actinides. All of the actinides are radioactive and those above Z=92 are manmade in nuclear reactors or accelerators.
The general properties of the transition elements are
They are usually high melting point metals.
They have several oxidation states.
They usually form colored compounds.
They are often paramagnetic. |
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Term
What are metals in the periodic chart and where are they located |
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Definition
Elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity. Most are malleable and ductile.
Includes all the elements 1A, 2A, & 3A except for Hydrogen & Boron
Includes all the elements in the D block and seven from the P block. |
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What are S block elements |
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Definition
elements whose valence consists of partially or completely filled S orbitals |
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What are P block elements |
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Definition
elements whose valence consists of partially or completely filled P orbitals |
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What are D block elements |
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Definition
elements whose valence consists of completely filled S orbitals and filled or partially filled lower level D orbitals.
there are some exceptions.
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What is the period on the periodic table |
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Definition
the rows of the periodic table that indicate what energy level the valence electrons reside upon |
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What is the group number on the periodic chart |
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Definition
The columns of the periodic chart.
For the representative elements this indicates the number of electrons in the valence electron (except for helium) |
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Term
What are the trends relating to atomic size in the periodic chart |
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Definition
Applies to Representative Elements only.
From left to right in a period the atomic radius decreases because of the increasing positive charge as more protons are added.
From top to bottom in a group the atomic radius increases because additional energy levels are filled that are further away from the nucleus. They are not pulled in closer to the nucleus because of the shielding effect of lower energy level electrons and the electrons are further away and therefore experience less positive pull. |
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Term
What are the trends in the periodic table concerning elements forming Ions |
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Definition
True for representative elements only
Metals & Metaloids are more likely to lose an electron and become more positive. This trend begins in the first group on the left side of the periodic table. As you move from left to right in the period the elements can form more positive ions.
The metaloids Arsenic & Tellurium are exceptions as they form negative ions
The non-metals in Group 4 which have 4 electrons in their valence and can gain 4 more to become balanced or lose 4 to become balanced act like metals and can form +4 ions.
Non-metals are generally more likely to gain an electron and form negative ions except for the non-metals in the 4th group.
Non-metals in the 5th group can form -3 ions and trend towards becoming less negative as they move to the right in the period.
The noble gases in the 8th group are non-reactive and do not form ions.
The value of the ionic charge is based on the number of electrons you can lose for the left side of the periodic chart. Group 1 has one electron and can only form a +1 ion. Group 4 has four electrons and can form up to +4 ions.
On the right side of the periodic chart where elements form negative ions, the value is based on how many electrons you can gain to become balanced with 8 electrons. So the group 6 elements can form -2 ions while the group 7 elements can form -1 ions.
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Term
What is ionization energy |
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Definition
the amount of energy required to remove an electron from the atom or molecule in the gaseous state
Indicates how strongly an atom holds onto its electrons. Elements with high inonization energy will be unlikely to form positive ions |
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Term
What is electronegativity |
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Definition
Applies to representative elements only and does not apply to Group 8 elements
The ability of an atom to attract electrons in a chemical bond.
Electronegativity tends to increase as you move to the right on the periodic chart and decrease as you move from top to bottom in a group.
high electronegative elements which bond with low electronegative elements will tend to steal an electron from the lower electronegative element. They will then form a polar bond.
elements with similar electronegativity levels will tend to form covalent bonds and share electrons. |
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Term
Hydrogen
Symbol
Atomic Number
Group
Period
Approximate Atomic Weight
Approximate Electronegativity
Classification
Standard State at 298K (room temp)
Common Isotopes
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Definition
H
1
A1
1st Energy Level
1.0 amu
2.2 Paulings
Non-Metallic
Gas
Protium 0 neutrons
Deuterium 1 neutron
Tritium 2 neutrons |
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Term
Helium
Symbol
Atomic Number
Group
Period
Approximate Atomic Weight
Approximate Electronegativity
Classification
Standard State at 298K (room temp)
Common Isotopes
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Definition
He
Atomic Number 2
8A Group
1st Period
4.00 amu
0 Paulings
Noble Gas
Gas
3He - trace amounts
4He - produced by alpha decay of heavier radioactive elements
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