Atomic size refers to the radius of an atom. The atomic size may be visualized as the distance between the centre of the nucleus and the outermost shell of an isolated atom.
The atomic radius of the hydrogen atom is 37 pm pm. Atomic size decreases in going from
left to right along a period.
U (3)
Be (4)
F 19)
B (5)
C(6)
N17
OB)
Elements of 2
period atomic radius
(pm)
133
89
BD
77
66
70
N (111)
Al (13)
Mg (12)
Si (14)
5 (16)
CI (171
P (15)
Elements of 3
period atomic radius
(pm)
154
136
125
117
110
104
99
Q17. (i) Identify the reason for the decrease of atomic size in the period-

Salicylic acid is a very important acid. it is used to synthesize the aspirin by treating with acetic anhydride. a 0.2015-g sample of salicylic acid was dissolved in a 100.00-ml volumetric flask, and the solution was diluted to the mark. a 10-ml aliquot of this solution was titrated with standard naoh (0.01130 + 0.2% n) to a phenolphthalein faint pink color end point at 19.81 ml. (a) (calculate the normality of the salicylic acid solution used in the titration. (b) assuming the salicylic acid is pure, what is the equivalent weight of the salicylic acid? practice problems for the final exam (continued) (c) (calculate the inherent error in the determination of the equivalent weight you calculated in part (b). use the following absolute errors in the equipment /glassware when calculating the inherent error. 5.00-ml pipet: + 0.02 ml 100-ml volumetric flask: + 0.08 ml analytical balance: + 0.2 mg 25-ml buret: + 0.03 ml

0.09 moles of sodium sulfate in 12 ml of solution

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?