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

Explanation:

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

Explanation:

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