7. the periodic table used today is arranged by increasing *
a. mass numbers
b. electrons in the nucleus
c. atomic numbers
d. charge

8. how many neutrons are there in an atom of phosphorus- 31? *
a. 14
b. 16
c. 31
d. 46

9. the average atomic mass for an element depends on *
a. the mass and percentage that exists of each naturally occurring isotope
b. the mass and number of protons of each artificial isotope
c. the mass and position of the electrons in each isotope
d. the average of the relative abundance of neutrons in all isotopes

You have a liquid that exhibits diltancy. you want to pour it from a bottle. what should you do to the bottle before pouring

What’s the theoretical yield of solid lead

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .