(Q).
Q: The validity of thought experiments, of course, is determined by this? Choices: - predictive observation - theoretical observation - hypothetical observation - actual observation A:
(A).
actual observation

(Q).
Q: What type of isotopes have short half-lives and are given in very low doses? Choices: - stable isotopes - gasses - radionuclides - radioisotopes A:
(A).
radioisotopes

(Q).
Q: When magma cools slowly, what texture does it have? Choices: - large squares - large gases - small circles - large crystals A:
(A).
large crystals