Time period of revolution of an electron in nth orbit in a hydrogen like atom is given by T =
Tona
. Z
Zb
= atomic number
(1) To = 1.5 * 10-16 s, a = 3
(2) T. = 6.6 x 1015 s, a = 3
(3) To = 1.51 * 10-16 s, b = 3
(4) T. = 6.6 x 1015 s, b = 3

if you already have the answer to (a), then just work out how many periods there are in 1 minute, and that's the answer to (c).

uranium fissions/breaks up giving out energy and neutrons

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

explanation:

wheres the pic