21. After 62.0 hours, 1.0 gram of 42K (half-life is 12.4 hours) remained from a sample. What was the mass of42K in the original sample?(A) 64 grams (B) 32 grams (C) 16 grams (D) 8 grams

22. Of the statements below, which one can best explain why CH4 is a gas at STP, while C8H18 is a liquid and C20H42 is a solid? (A) C20H42 has the greatest ionic interaction between its molecules. (B) C8H18 has a greater amount of hydrogen bonding than CH4 or C20H42. (C) There is more dipole-dipole interaction between molecules of greater mass. (D) There are more Van der Waals (dispersion) forces between nonpolar molecules that are greater in mass.

21. After 62.0 hours, 1.0 gram of ⁴²K (half-life is 12.4 hours) remained from a sample. What was the mass of
42K in the original sample?
(A) 64 grams
(B) 32 grams
(C) 16 grams
(D) 8 grams

相關試題

相關試卷

21. After 62.0 hours, 1.0 gram of 42K (half-life is 12.4 hours) remained from a sample. What was the mass of42K in the original sample?(A) 64 grams(B) 32 grams(C) 16 grams(D) 8 grams

相關試題

相關試卷

21. After 62.0 hours, 1.0 gram of ⁴²K (half-life is 12.4 hours) remained from a sample. What was the mass of
42K in the original sample?
(A) 64 grams
(B) 32 grams
(C) 16 grams
(D) 8 grams