(07.05 HC A scientist investigating electrically-charged objects has decided to test if the number of times you rub a cloth against a balloon increases the amount of time it will stick to the wall. She wrote down her variables in a table. Variable Description Test The numbers of times she rubbed the cloth against the balloon Outcome The length of times the balloon sticks to the wall Control The cloth used in the experiment What would be her hypothesis for this experiment? (2 points) If you stick the balloon to a wall, then it will become electrically charged and stay there for a long period of time If you change the cloth used to change a balloon

How is energy related to the change of state represented by the model? atoms gain energy as a solid changes to a liquid. atoms gain energy as a solid changes to a gas. atoms lose energy as a solid changes to a liquid. atoms lose energy as a solid changes to a gas.

Which of the following changes will decrease the total amount of gaseous solute able to be dissolved in a liter of liquid water? (2 points) decreasing temperature decreasing pressure decreasing surface area decreasing solute concentration

Suppose a pair of chemical compounds a and b can react in two different ways: a + b -> c reaction 1 gives product c. a + b -> d reaction 2 gives product d. the following facts are known about the two reactions: . reaction 1 is endothermic and reaction 2 is exothermic. if a reaction vessel is charged (filled) with a and b , then at first d is produced faster than c. use these facts to sketch a qualitative reaction energy diagram for both reactions. note: because these sketches are only qualitative, the energies don? t have to be exact. they only have to have the right relationship to each other. for example, if one energy is less than another, that fact should be clear in your sketch.