the mass of cobalt-60 in a sample is found to have decreased from 80 grams to 30 grams in a period of 10.5 years. Calculate the half-life for cobalt-60

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same