Three magnesium isotopes have atomic masses and relative abundances of 24 amu (79.0%), 25 amu (10.0%), and 26 amu (11.0%). Calculate the atomic mass of magnesium.

If two atoms are bonded to a central atom with no lone pairs,how will they be arranged

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.

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2