Ablock of lead weighed 1591 g and has dimensions 4.50cm by 5.20 cm by 6.00 cm calculate the density of lead from this information

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Which metal exist in liquid state and can be cut with knife ?

Answer asap need 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.