What is the mass of a rock that weighs 49 newtons? a. 1 kilogram b. 2 kilograms c. 5 kilograms d. 10 kilograms

Calculate the change in entropy if br2(l) is converted to br2(g). s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

Apeak with a retention time of 407 s has a width at half-height (w1/2) of 7.6 s. a neighboring peak is eluted 17 s later with a w1/2 of 9.4 s. a compound that is known not to be retained was eluted in 2.5 s. the peaks are not baseline resolved. how many theoretical plates would be needed to achieve a resolution of 1.5?

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen