In an experiment, you test whether the number of times you rub a cloth against a balloon changes how long it will stick against the wall. You start by rubbing the balloon 10 times with the cloth and stick it to the wall. You repeat this three times and record your results in a table. Observation
Number of Times Balloon is Rubbed by Cloth Trial #1 Trial #2 Trial #3
10 6 seconds 20 seconds 20 seconds
What statement best reflects why you should do repeated trials in an experiment?

When the volume and number of particles of a gas are constant which of the following is also constant

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

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.