A different element, , is located in the same row of the periodic table as element , but has roughly half the atomic mass of . Is the atomic radius of less than, equal to, or greater than the atomic radius of ? Justify your answer using principles of atomic structure.

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

12. calculate the hydroxide ion concentration of a solution with ph = 3.25. show all calculations leading to an answer

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]