Explanation:
Henri Becquerel discovered radioactivity in 1896 while studying uranium salts. Marie and Pierre Curie further investigated radioactive elements. Rutherford studied alpha/beta radiation.
Explanation:
Iodine sublimes on heating, converting to vapor, leaving sand behind. Iodine vapors can be condensed. Filtration cannot separate two solids; distillation for liquids.
Explanation:
A solution turning red litmus blue is basic, so pH > 7. Among options, pH 9 is basic. pH 2 and 5 are acidic (blue litmus turns red). pH 7 is neutral. Litmus is a natural indicator extracted from lichens. Red litmus in base remains blue, blue litmus in acid turns red. Practical: Phenolphthalein gives pink in basic solution (pH > 8.3).
No comments yet. Be the first to start the discussion!