An element in this group is attached to the alpha carbon of a carboxylic acid in the Hell-Volhard-Zelinsky (10[2]-5[1])reaction. In mass spec, (10[1])two peaks (10[1])of equal height (10[2])two units apart characterize (10[2])a member (10[1])of this group. (10[3]-5[2])An atom (10[2])of a member of this group is displaced (10[1])in a positive silver nitrate (10[3])test. (10[1]-5[2])Adding magnesium (10[1]-5[1])to hydrocarbons containing a member of this group (10[2])creates Grignard (10[2])(“grin-yard”) reagents. (10[2]-5[1])These elements, (-5[1])which are denoted with an X (10[1])in organic (10[2])structures, (10[3])can replace (10[1])hydrogen (10[1]-5[1])since they both require one more (10[1])electron (-5[1])for a full (10[1])outer shell. (10[3]-5[1])For 10 points, (10[1])name this group of elements (10[1])with seven valence electrons, (10[2])including (10[1])fluorine and chlorine. (10[3]0[1])■END■ (10[5])