Within which of these layers does convection occur?
a. mantle and crust
b. inner core and crust
c. outer core and mantle
d. inner core and outer core

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

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.