Answer:
Lithium diisopropylamide [(CH3)2CH]2NLi.
Explanation:
Lithium diisopropylamide (commonly abbreviated LDA) is a chemical compound with the molecular formula [(CH3)2CH]2NLi. It is used as a strong base and has been widely accepted due to its good solubility in non-polar organic solvents and non-nucleophilic nature. It is a colorless solid, but is usually generated and observed only in solution. It was first prepared by Hamell and Levine in 1950 along with several other hindered lithium diorganylamides to effect the deprotonation of esters at the α position without attack of the carbonyl group.
Answer is: 4 atoms of nitrogen.
One formula unit of magnesium nitrate (Mg(NO₃)₂) has two atoms of nitrogen, so two formula units of magnesium nitrate will have four atoms of nitrogen (2·2=4).
Oxidation number of magnesium in magnesium nitrate is +2 and oxidation number of nitrate anion is -1 (2·(-1) = -2).
C.) Surface Tension, Because water can hold a certain amount of pressure/weight before the object sinks