Group 3 and Group 6

Solubility Curves Basic Info: Solute-Dissolved substance in a solution i.e. salt or O 2 Solvent-Dissolving agent in a solution i.e. water Solubility-Maximum quantity of a substance that will dissolve in a given amount of solvent to form a saturated solution. Saturated Solution-solution in which the solvent has dissolved as much solute as it can contain stably at a given temperature. OR no more stuff can be dissolved. Unsaturated Solution- solution a lower concentration of solute than a saturated solution at a given temperature. OR more stuff can be dissolved. Supersaturated Solution- solution containing a higher concentration of solute than a saturated solution at a given temperature. OR even though more stuff could dissolve, extra stuff was forced into dissolving. Supersaturated solutions are very unstable.

Solubility of Gases As Temp. increases, solubility decreases. This is true for all gases. Points on solubility curves represent the amount of solute that saturates a solution at a given temp.

Solubility of Solids As Temp. increases, solubility increases. This is true for all solids.

Acid vs. Base Acid- A solution with a higher concentration of hydronium ions than hydroxide ions Base- A solution with a higher concentration of hydroxide ions than hydronium ions pH Scale- Measurement of acidic or basic characteristics in a solution

Litmus Paper- Special paper that measures acidity. Turns blue when in contact with a basic solution and red when in contact with an acidic solution

Identifying Acids and Bases Acids are characterized by H+ ions and bases are identified by OH- ions in ionic compounds. HCL- acid NaOH- base Look for H as the cation for acids Look for OH- as the anion for bases

Arrangement of Periodic Table Family Period Modern

Mendeleev’s Periodic Table

Periodic Tables Modern1800’s Progressive horizontally organized by atomic number Metals on the right; nonmetals on the left; metalloids in the middle Rightmost column is noble gases- least reactive gases Organized according to mass and reactivity with other elements Similar properties were placed in columns Horizontally arranged by atomic weight

Periodic Trends Valence electrons- The electrons of an atom in the outer most energy shell. These are the electrons that participate in chemical reactions. Energy level- Expression of the relative potential energy possessed by electrons located within an atom. Valence shell- Outer most shell Valence shell

Families have the same number of valence electrons but the number of energy levels per element increase by one going down. Number of valence electrons increase by one from left to right Families of elements form the same ions and have same ionic charges. They also have similar physical and chemical properties.

Predicting formula units CaCl2 BCl3 Na2O K and Se- would form K2Se because K is in the same family as Na and Se as O. Sr and I- would form SrI2 because Sr is in the same family as Ca and I as Cl.