3.4 Study Guide

STUDY
PLAY

Terms in this set (...)

Periodic table
a chart that shows all the known elements and gives specific info about each
Dmitri Mendeleev
-Invented the 1st periodic table
-arranged in order of increasing atomic mass and similar chemical properties
-left gaps where new elements would fit
-estimated atomic mass
Modern Atomic elements
-elements listed in order of increasing atomic number (number of protons)
periods
horizontal rows
groups/families
-vertical columns
-elements in it have similar properties
-certain columns have special names that describe particular chemical properties
group 1
akali metals (except H)
group 2
alkaline earth metals
group 7
halogens
group 8
noble gases
large middle section
transition metals
1st row at the bottom
lanthanides
2nd row at the bottom
actinides
3 types of elements
1. nonmetals
2.metals
3.metalloids
Metals
-largest group
-good conductors
-varying boiling and melting points
-usually lustrous and malleable
-form alloys with other elements
Nonmetals
-small group (compared to metals)
-physical properties are opposite of metals
-brittle
-poor conductors of heat and electricity
-dull
-variable melting and boiling points
Metalloids
-properties of nonmetals and metals
-all solids
Silicon
the most prevalent semi-conductor in nature and society
Most elements....
are very reactive and are not found in nature in their pure form
Diatomic elements
hydrogen, nitrogen, chlorine, bromine, iodine, flourine and oxygen
Allotropes
substances made from the same element but with different structural arrangements
Examples of allotropes
diamonds, carbon, and graphite
why do we often find elements in their pure form in nature?
their atoms tend to combine with those of other elements to form compounds quite readily
three noble metals
gold, silver, platinum
behavior of elements in group 8
relatively unreactive
3 elements in the mixture we call air
argon, nitrogen, oxygen
same properties allotropes?
because of their different structures