Copper has two naturally occurring isotopes. The isotope Cu-63 (mass 62.93amu) makes up 69.17% of the sample, and the isotope Cu-65 (mass =
64.98amu) makes up 30.83% of the sample. What is the average atomic
mass for chlorine?

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.

An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of amu. (enter a whole number.) numerical answers expected! answer for blank 1:

When a device is used in a circuit in which the voltage is 81 v the current flowing through the device is 3 a what is the resistance of the device