Water is a good choice of solvent because it is benign, cheap and readily available. Identify two characteristics that make water a good choice for the recrystallization solvent for benzoic acid? (What are the characteristics of a good recrystallization solvent?)

Explanation:

It is known that a compound is soluble when the boiling point of the solvent is high. Whereas at normal temperature of the solvent it will have low solubility.

And, if the solute is highly soluble into the solvent at normal temperature then it is difficult to recrystallize the solute.

Hence, in order to recrystallize the solute particles it is necessary that impurities will be highly soluble at the room temperature or they should remain insoluble into the hot solvent.

As a result, there will not take place any reaction between the solute and solvent.

Since, benzoic acid is non-polar in nature and water is a polar solvent so, it will not easily dissolve in water. Therefore, it will readily evaporate in order to give the pure compound.

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.  

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.