A student cut out a spiral shape from a piece of tissue paper and hung it from a string over a light bulb. Nothing happened. Next the student turned on the light. After a few seconds, the spiral began to turn above the light. Which of these best explains what happened?

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

1) in saturated limewater, [h+ ]=3.98x10-13 m. a) find [oh]-/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 2) in butter, [h+ ]=6.0x10-7 m. a) find [oh]-/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 3) in peaches, [oh]=3.16x10-11 m a) find [h+ ]/ b) what is the ph? / c) is the solution acidic, basic, or neutral? / 4) during the course of the day, human saliva varies between being acidic and basic. if [oh]=3.16x10-8 m, a) find [h+ ]/ b) what is the ph? / c) is the solution acidic, basic, or neutral? /

Nconcentration refers to the molar concentration of an ion in solution. it may be identical to, or greater or less than, the molar concentration of the compound containing the ion that was used to make the solution. for soluble salts, the molarity of a particular ion is equal to the molarity of that compound times the subscript for that ion. for example, 1 m of alcl3 is 1 m in al3+ and 3 m in cl−. 1 m of (nh4)2so4 is 2 m in nh4+ and 1 m in so42−. part a what is the concentration of k+ in 0.15 m of k2s? view available hint(s) nothing m m part b if cacl2 is dissolved in water, what can be said about the concentration of the ca2+ ion? view available hint(s) if is dissolved in water, what can be said about the concentration of the ion? it has the same concentration as the cl− ion. its concentration is half that of the cl− ion. its concentration is twice that of the cl− ion. its concentration is one-third that of the cl− ion. part c a scientist wants to make a solution of tribasic sodium phosphate, na3po4, for a laboratory experiment. how many grams of na3po4 will be needed to produce 550 ml of a solution that has a concentration of na+ ions of 0.700 m ? express your answer numerically in grams. view available hint(s) mass of na3po4 n a 3 p o 4 = nothing g provide feedback