Unit 3: Periodic Table + Nomenclature

How are groups and periods different?

Groups are: columns

Periods are: rows

groups

are found in vertical columns. There are 8 representative groups (#1A-8A) whose elements have similar properties (also known as periodic trends). *the first group is all extremely reactive, the last group is completely unreactive.

atoms

are neutral since P=E

how do atoms become ions?

when they gain or lose electrons

How many electrons fit on each level?

1st: 2

2nd: 8

3rd: 8/18 ( 1 set of 8, then a set of 10)

how to name cations (metals)

most are names as-is ex: Na+: sodium ion

how to name anions (nonmetals)

Change ending to -ide ex: F-:fluoride ion

periodic trends

Are the tendencies of certain elemental characteristics to increase or decrease within a period

what changes as you move across a period (or change groups from left to right)?

Number of valence electrons change

what family is group 1 in (excluding hydrogen)

alkali metal

what family is group 2

alkaline earth metals

what family is group 7

halogen

what family is group 8

Noble gases

alkali metals

• elements in group 1 (except for hydrogen)

• These elements are extremely reactive; as a result they exist mostly as compounds

• All have 1 valence electrons

Alkaline earth metals

• group 2 metals are called the alkaline earth metals 

• They are also highly reactive, but less reactive than the alkali metals of group 1

• All have 2 valence electrons e-

halogens

• group 7 nonmetals

• Highly reactive, so they are usually found in compounds

• All have 7 valence electrons

which two groups are the most reactive

halogens and alkali metals because its elements readily gain or lose valence electrons to achieve stable electron configuration.

Noble gases

• group 8 

• Extremely unreactive (inert) because they all have a full valence shell (don’t like to react)

inert

unreactive

Will metals typically lose or gain their valence electrons? What kinds of ions will they form?

Metals will lose their valence electrons and positive ions! 

Will nonmetals typically lose or gain their valence electrons? What kinds of ions will they form?

nonmetals will gain electrons to fill that shell and negative ions!

why is hydrogen unique?

it can both gain and lose electrons

Why is neon (a noble gas) unreactive while fluorine and sodium are very reactive?

Noble gases have their outer shell full. All other elements want full outer shells too, so they gain/lose/share e- to get full shells. 

Why does elements tend to gain, lose, or share electrons?

to achieve a filled outer electron shell (valence shell)

Good conductors

metals

bad conductors

nonmetals

metals

• elements to the left of the staircase (except hydrogen) 

• Characteristics: shiny (luster), ductile (can be cut or stretched into wires), malleable (can be bent or pounded into thin sheets), usually solid at room temp (except mercury), good conductors of electricity and heat, usually react to acids and copper chloride 

nonmetals

• generally on right side of periodic table (except hydrogen)

• Characteristics: some are gases, some are solids, only liquid is bromine, dull-looking, brittle solids, poor conductors of heat and electricity, do not react to acids/bases

metalloids

• located on either side of the staircase except for aluminum 

• Have physical and chemical characteristics of both metals and nonmetals 

Covalent bonds 

• are between nonmetal atoms that share electrons in order to complete their valence shells 

• after nonmetals are bonded they are called molecules

• No cations or anions are formed since the electrons are not completely lost or gained by either atom 

which formula are ionic compounds always represented by?

empirical formula

how do you name molecular compounds

1. Name the non-metal furtherest to the left on the periodic table

2. Name the other non-metal by its name with an -ide ending

3. Use prefixes (mono-, di-, tri-, etc) to indicate the number of each element in the molecule

polyatomic ions

Contains more than one atom with an overall charge - these are used in ionic bonding

polyatomic molecules 

do not have an overall charge - but instead are the products of covalent bonds

acids w/ polyatomic ion. Binary -ide

hydro____ic acid

polyatomic -ite →

-ous

polyatomic -ate →

-ic

What does an ionic bond result from?

the combination of a metal and a nonmetal

how are covalent bonds formed

by neutral atoms that share electrons rather than by charged ions

molecule 

when a compound is formed by sharing electrons 

what formulas can molecules be represented by?

molecular formula or empirical formula

what does the molecular formula tell you

exactly how many atoms of each element are in the compound

what is an empirical formula

ratio of elements in a compound