Transcript Periodic table trends

Elements
What is an element?
• An element is a pure substance that is
not combined with any other substance
nor can be broken down any farther
Periodic table
• Elements are arranged on the periodic
table by varying factors such as atomic
structure (how the subatomic particles
such as protons, neutrons and electrons
are arranged), reactivity, melting point
and ionization energy
Periodic Table
• Columns up and down the table are
called families or groups.
• Rows across the table are called
periods.
Atomic size
• As you go DOWN a family size
INCREASES
• As you go ACROSS a period size
DECREASES
• So…biggest atoms are in the bottom left
corner of the table
Reactivity
• Reactivity is how likely and violently the
atom will react with other substances
• Metals- reactivity decreases across a
period and increases down a family
• Non-metals- reactivity increases across
a period and decreases down a family
Melting point
• Metals- decreases as you go down a
family
• Non-metals- increases as you go down
a family
Ionization energy
• Ionization energy is the amount of
energy required to remove the
outermost electron
• Increases as you move across a period
and decreases as you go down a group