27. using the information in parent-daughter material, which of the isotope pairs might be used to
determine the age of something that was once living?
a. c-14 & n-14
c. any of these could be used
b. k-40 & ar 40
d. u-235 & pb-206

If you want to create an electrical current, which situation would produce a solution capable of this

Which of these is not an example of chemical weathering? a. iron-rich mineral rusting b. feldspar turning into clay c. limestone reacting with acid d. granite breaking up into sand

Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?