An isotope is known to have a half-live of 50.53 days. How much of a 150.00 g sample remains after 252.65 days? Please Answer! Need help!!

Amass of 100.0 g of solute is dissolved in water so that 850. ml of a 0.7500 m solution has been prepared. what is the molar mass of the solute?

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?