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

What is impossible to do with a hypothesis

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?