Which of the following statements is a valid hypothesis?
the atmosphere contains more nitrogen than oxygen.
alien spaceships cause crop circles to form.
why are most plants green in color?
a frog jumps more often when it is feeling happy.

Janel’s class studied properties of matter and how matter can change. janel decided she would do an experiment mixing baking soda and vinegar.question: describe the properties of baking soda and vinegar, and explain the changes that janel should see when she mixes the two types of matter. •first, identify the physical state of matter of baking soda. describe another property of baking soda. •next, identify the physical state of matter of vinegar. describe another property of vinegar. •then, explain what janel should see when she mixes the baking soda and vinegar. •describe the states of matter of the new materials that are formed. •explain how janel can be certain a change has occurred. me

10-14. (a) when 100.0 ml of weak acid ha were titrated with 0.093 81 m naoh, 27.63 ml were required to reach the equivalence point. find the molarity of ha. (b) what is the formal concentration of a- at the equivalence point? (c) the ph at the equivalence point was 10.99. find pk. for ha. (d) what was the ph when only 19.47 ml of naoh had been added?

Which part of a feedback mechanism is able to monitor the conditions outside of cells and usually uses nerve cells to relay this information to an intergrating center