according to the bohr model of an atom, what happens when an electron moves from the second energy level to the third energy level and then back to the second energy level?

Melissa is interested in her family tree and how her family has changed over its many generations. melissa probably more closely resembles

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.

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver