The Periodic Table

he set up the 1st periodic table according to increasing atomic mass

Dmitri Mendeleev

the way he set up the table, he was able to predict the presence of some elements that were not yet discovered

Dmitri Mendeleev

he set up the modern-day periodic table according to increasing atomic number

Henry Moseley

by arranging the table this way, elements with similar properties were able to be kept together 

Henry Moseley

the mass of an atom is expressed in __ __ ___. it is equal to 1/12 the mass of a carbon-12 atom

atomic mass unit (amu)

the atomic mass listed for an element on the periodic table is a _____ because it is the average atomic mass of all of the isotopes of that element

decimal

elements on the periodic table are classified a few different ways:

• as ________

• as naturally occurring and those that do not occur naturally _______

• as _________

solids, liquids, gases

synthetic

metals, nonmetals, metaliods

the majority of elements on the periodic table are ____

metals

located to the left of the zig-zag line

metals

metals are ____ conductors of heat and electricity, mostly ____, ____ have____ and are ___

goods

solids, malleable

luster and are ductile

located to the right of the zig-zag line

nonmetals

nonmetals have properties that are ____ of metals

opposite

nonmetals are ___ conductors of heat and electricity, ___, are mostly liquids and gases, and have ___ luster

poor

brittle

no

border the zigzag line

metalloids

have properties between metals and nonmetals

metalloids

metalloids are ___-___,: usually a solid chemical element or compound that can conduct electricity under __ conditions but not others

semi-conductors

some

the vertical columns on the period table are called ___, or ___. there are __ vertical groups.

groups, families

18

• elements in the same group or family have ____ properties

• they have similar ___ configurations which determine its chemical properties

similar

electron

the horizontal rows on the periodic tables are called ____ and there are __

periods

7

across a period from left to right the elements properties change (they become ___ metallic and ____ nonmetallic)

less

more

electrons that are located in the outermost energy level of the atom

Valence electrons

elements in a group have similar properties they because they have the ____ # of valence electrons

same

the # of valence electrons also determine the atom’s ability to ____ ___ with other atoms

form bonds

group # determines the valence electron:

1 and 2: the group number is the ___ ___

13 to 18: ___ 10 from the group number

valence electron

subtract

group 1 on the periodic table

group one has _ valence electron

alkali metals

1

the most reactive metals so they are usually not found alone in nature (they are found combined as compounds)

alkali metals

soft metals, have low melting points and low densities”

alkali metals

group 2 of the periodic table

_ valence electrons

alkaline earth metals

2

reactive but not as reactive as group 1

alkaline earth metals

groups 3-12 on the periodic table

____ to ___ valence electrons

transition metals

1 to 3

less reactive than alkaline- earth metals

transition metals

have properties such as conducts heat and electricity, malleable, ductile. (normal metal properties)

transition metals

the only metal liquid at room temperature 

mercury

the last 2 rows at the bottom of the periodic (part of 6 and 7)

rare-earth metals

placed there to make the table a more convenient size

rare-earth metals

some elements are synthetic (created in labs) and some are radioactive

most have no uses

rare-earth metals

group 13 on the periodic table

_ valence electrons

boron group

3

the boron group

__- most abundant metal in the earth’s crust (cans, gutters, siding)

__- used to make lab glassware that doesn’t shatter when it undergoes a rapid change in temperature

Al

B