. Three students are asked to discuss the percent error obtained in this lab.
Select the student that employs correct scientific reasoning.
Student 1: The percent error could be caused by mixing the reaction too quickly, the friction
caused by mixing would increase the change in heat measured.
• Student 2: The percent error could be caused by the salt not completely dissolving, therefore the
change in heat per mole would be accidentally low.
. Student 3: The percent error could be caused by the change in pH of the solution, this would
decrease the change in heat accidentally.
O Student 2
O Student 3
O Student 1

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.

the answer is c.the valence of the atoms combine .

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.