Periodic Table 

Periodic Trends:

Atoms have an electron cloud surrounding the nucleus

(the radius varies from element to element)

• %%As you move left to right across a period, the atomic radii generally DECREASES%%
• %%As you move down a group, the atomic radii generally INCREASES%%

Explanation:

Ionization Energy in simple terms is basically how much an atom wants their electrons…

==High ionization energy:== Strong hold on to electrons

(unlikely to become positive ions)

==Low ionization energy:== Weak hold on to electrons

(likely to become positive ions)

• ==As you move across periods from left to right, ionization energy INCREASES==
• ==As you move down groups, ionization energy DECREASES==

Octet Rule: Atoms tend to gain, lose, or share electrons in order to acquire a full set of 8 valence electrons

Electronegativity is the ability of an element to attract electrons…or basically how bad does it want another electron

• @@As you move from left to right, the electronegativity INCREASES@@
• @@As you move down a group, the electronegativity DECREASES@@

Types of Elements:

==Metals:==

• mostly all to the left, and it’s 75% of all elements
• malleable, ductile, luster, and conducts electricity
• more metallic as you go down a group, towards the left

==Nonmetals:==

• mostly gases
• dull, poor electrical conductors
• mostly to the right of the table
• brittle and lack metallic luster in the solid phase
• doesn’t conduct heat/electricity in the solid phase
• NOBLE GASES ARE MONOATOMIC (don’t bond with other atoms)

==Metalloids:==

• some properties of metals, and others of nonmetals
• staircase that separates the metals/non-metals
  • B, Si, Ge, As, Sb, Te

Using the Period Table:

Elements in the same group have similar chemical and physical properties !

• Same number of valence electrons
• form the same kind of ions, meaning they’ll combine with other elements the same way

These groups are a family, and each has their own specific name to differentiate it

• Elements in each family react differently with other elements

$Group 1: Alkali Metals$

• Hydrogen doesn’t count, as it’s a non-metal ***
• 1 electron in the outer shell (valence electron)
• Soft and silvery metals
• VERY reactive, esp. with water
• Conducts electricity

$Group 2: Alkaline Earth Metals$

• 2 electrons in the outer shell
• White and malleable
• Reactive, but less than Alkali metals
• Conducts electricity

$Groups in the middle: Transition Metals$

• Groups in the middle
• Good conductors of heat/electricity
• Used for jewelry
• Bonds with many elements in varieties of shapes

$Group 3: Boron Family$

• 3 electrons in the outer shell
• most are metals, but boron is a METALLOID

$Group 4: Carbon Family$

• 4 electrons in the outer shell
• contains metals, metalloids, and a NON-METAL (carbon)

$Group 5: Nitrogen Family$

• 5 electrons in the outer shell
• could share electrons to form compounds
• contains metals, metalloids and non-metals

$Group 6: Oxygen Family$

• 6 electrons in the outer shell
• contains metals, metalloids, and non-metals
• reactive

$Group 7: Halogens$

• 7 electrons in the outer shell
• all are non-metals
• VERY reactive, and often bond with elements from group 1
• always found combined with another element in nature and stays DIATOMIC when by itself

Group 8: Noble Gases

• exist as gases
• non-metals
• 8 electrons in the outer shell
  • helium, with 2 electrons in outer shell is an exception
• NOT REACTIVE with other elements, due to already full valence shell

3 types of Elements (characteristics)

Metals:

Chemical properties:

• tend to lose electrons easily
• have low ionization energies
• form positive ions when combining with other atoms

Physical properties:

• good conductors of heat and electricity
• lustrous- reflect light, shine when they are polished
• flexible
• malleable
• ductile
• are solids at room temperature (except for mercury)

Nonmetals:

chemical properties:

• tend to gain electrons
• produce covalent bonds by sharing electrons with other nonmetals

physical properties:

• exist as gases, molecular solids, or network solids at room temperature except BROMINE
• solids are brittle (not ductile or malleable)
• solids are dull
• poor conductors of heat and electricity

Metalloids:

• elements at the border in between metals and nonmetals have some properties of both