Understanding the Periodic Table: Groups, Periods, and Properties of Elements, Exercises of Chemistry

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PERIODIC TABLE

PERIODIC TABLE

• A visual representation used in Science to organize the

elements according to their chemical and physical properties

• When talking about the Periodic Table, you will hear words like:
  • Group
  • Family
  • Period
  • Valence electrons
  • Energy levels

PERIODIC TABLE

• Group or Family
  • You will see that on the Periodic Table they are numbered (IA,

IIA, IIB, etc)

• Each group/family also has a name (we’ll come back to this in a

bit)

PERIODIC TABLE

• Period (orbits, energy levels, energy shells)
  • All the elements in a single row on the periodic table are said to be

in the same period

• All elements in the same period have the same number of electron

shells (orbits)

Periods

(same number of shells)

PERIODIC TABLE

• Staircase
  • You’ll also notice that there is a staircase along part of the Periodic

Table

• This staircase divides the metals from the non-metals
  • Most elements along the staircase are metalloids

A NOTE ON HYDROGEN

Hydrogen

You’ll notice that hydrogen is labelled as a non-metal even though it is

placed on the side with the metals; this is because it does not exhibit

most of the characteristics required to be a metal (we’ll discuss these

shortly)

But sometimes it does act like a metal…

For our purposes, it is a non-metal!

PROPERTIES OF METALS, NON-METALS AND METALLOIDS

• Metals:
  • Left of the staircase
  • Metallic lustre
  • Good heat conductors
  • Good electrical conductors
  • Malleable
  • Ductile
  • Very reactive when placed in water and acid
  • High melting point
  • All solid at room temperature (except mercury)

PROPERTIES OF METALS, NON-METALS AND METALLOIDS

• Non-Metals:
  • Right of the staircase
  • Opposite properties of metals:
    • No metallic lustre
    • Do not conduct heat or electricity well
    • Not malleable
    • Not ductile
    • Do not react violently with acids or water
  • Can be solid, liquid or gas at room temperature

PROPERTIES OF METALS, NON-METALS AND METALLOIDS

• Metalloids:
  • Along the staircase
  • Exhibit some characteristics of metals AND some of non-metals
    • Ex: shiny (like a metal) but not malleable (like a non-metal)

GROUP NAMES & CHARACTERISTICS

• Alkali metals
  • First group on the left (does not include hydrogen ← remember, not a metal)
  • The most reactive family
    • Because each element only has one valence electron
  • Obviously, have all the properties of metals

GROUP NAMES & CHARACTERISTICS

• Alkaline earth metals
  • Second group from the left (starts with Beryllium)
  • Very reactive but not as much as alkali metals
  • Again, have all the properties of metals

GROUP NAMES & CHARACTERISTICS

• Groups 3A, 4A, 5A and 6A
  • Just named after the first element in the group
    • Ex: Boron family, Carbon family, etc FYI: They don’t usually ask you about these on the exam

GROUP NAMES & CHARACTERISTICS

• Halogens
  • Group 7A (begins with Fluorine)
  • Have all the characteristics of non-metals
  • If you mix a halogen with a metal , you’ll get a salt
    • Halogen + metal = salt
  • Used as disinfectants/antiseptics
    • Kills bacteria, fungi, etc

That’s why people use chlorine to keep

their pools from growing algae!