Chemistry Matter and Change Chap 6

What is ductility
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
What is malleable
able to be hammered or pressed permanently out of shape without breaking or cracking.
What was John Newland known for
First organization scheme for the elements
What was Mendeleev known for
Created first periodic table
What is the periodic law
There is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
What are Representative Elements

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.

 

 

 

What are Transition Elements

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.

What are metals in the periodic chart and where are they located

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.

What are S block elements
elements whose valence consists of partially or completely filled S orbitals
What are P block elements
elements whose valence consists of partially or completely filled P orbitals
What are D block elements

elements whose valence consists of completely filled S orbitals and filled or partially filled lower level D orbitals.

 

there are some exceptions.

 

 

What is the period on the periodic table
the rows of the periodic table that indicate what energy level the valence electrons reside upon
What is the group number on the periodic chart

The columns of the periodic chart.

 

For the representative elements this indicates the number of electrons in the valence electron (except for helium)

What are the trends relating to atomic size in the periodic chart

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.

What are the trends in the periodic table concerning elements forming Ions

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.

 

 

What is ionization energy

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

What is electronegativity

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.

Hydrogen

Symbol

Atomic Number

Group

Period

Approximate Atomic Weight

Approximate Electronegativity

Classification

Standard State at 298K (room temp)

Common Isotopes

 

H

1

A1

1st Energy Level

1.0 amu

2.2 Paulings

Non-Metallic

Gas

Protium 0 neutrons

Deuterium 1 neutron

Tritium 2 neutrons

Helium

 

Symbol

Atomic Number

Group

Period

Approximate Atomic Weight

Approximate Electronegativity

Classification

Standard State at 298K (room temp)

Common Isotopes

 

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