C4: Chemical Patterns

C4: Chemical Patterns

1. Development of the periodic table

   • 1. Dobereiner's Triad's
     • Dobereiner put the elements into groups of three based on their chemical properties.
     • The middle element had a RAM which was average of the other two.
   • 2. Newland's Octaves
     • Newlands noticed that when you put element in order of their relative atomic mass, every eight element had similar properties.
     • But the pattern broke down on the transition metals.
     • Newland's work was ignored by the chemical society because he didn't leave gaps for undiscovered elements, nor did his groups have similar properties.
   • 3. Mendleev
     • Mendleev left gaps and predicted new elements, he noticed the gaps needed to be made in order for each vertical group to have similar properties.
     • His ideas were confirmed when his predictions were proved to be correct.

2. Alkali Metals and Halogens

   • https://docs.google.com/document/d/1kc7gkZdgMY58vAz_3z2_l1K5Y5vU5zKUUdnfOLhcyDA/edit?usp=sharing

3. The Modern Periodic Table

   • puts elements with similar properties together, laid out in increasing proton number.
     • Arranging the elements like this means that there are repeating patterns in the properties of elements.
       • If you know the properties of one element in the group, you can predict the properties of other elements.
       • Making predictions about reactivity can be done because the elements are arranged in this way.
   • Rows= Periods
     • Colums= groups
   • Relative atomic mass= sum of protons and neutrons
   • 288

4. Ions and Formulas

   • Some metals, like iron, copper and tin form ions with different charges. The number of brackets after the name tells you the positive charge e.g. iron (II) has a charge of +2, so the ionic formula is Fe2+.
   • The charges on an ionic compound add up to 0.
     • To balance ionic formulas one must put numbers in front of the numbers, like a regular equation..

5. Ionic Bonding

   • Ions are made when atoms gain or loose electrons.
     • Group 1 become positive ions when they complete their outer shell.
     • Group 7 become negative ions when they complete their outer shell.
   • Transferring electrons
     • Oppositly charged ions are strongly attracted to each other. They stick to another oppositely charged ion and form an ionic bond.
       • Sodium and Chlorine
         • Chlorine (7) picks up sodium's spare electron and becomes a negative ion, as sodium (1) looses this electron it becomes positive. As the two ions are now strongly attracted to each other, they stick and form an ionic bond.
         • Solid ionic compounds (like sodium chloride) are made up of giant lattice of ions. Each lattice forms a single crystal.
           • The fact that the molten compounds of metals and non-metals can conduct electricity is proof that they're made up of ions.

6. Lab Safety

   • Oxidising
     • Provides oxygen which allows other materials to burn more fiercely.
   • Toxic
     • Can cause death either by swallowing, breathing in, or absorption through the skin.
   • Explosive
   • Highly Flammable
   • Corrosive
     • Attacks and destroys living tissue.

7. Line Spectrums

   • https://docs.google.com/document/d/1yQwKBSJze9ZKLAK9jqgzWxB0pJqiNL9QYv5KMgrsCxc/edit?usp=sharing

Imagens e arquivos do mapa