What is the percentage composition of sodium? (C=12 g/mol, N=14 g/mol, Na=23 g/mol, O=16 g/mol, H=1 g/mol)

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

Which process describes vaporization that takes place below the surface of a liquid? condensation melting boiling evaporation

In medium-sized stars such as the sun, nuclear fusion almost always means the fusing of nuclei to form , but larger stars can produce elements as heavy as