Chem help the boring questions?

Question

1, how many neutron, proton, electron are in Fe+2, Ca2+, how did u get it. ( i know proton, im not sure the neutron) does the +2 affect the neutron?

2. some dude propose to pay off the reparation imposed against the German by extract gold from seawater. given amt ofreparation was 28.8 billion dollars, the calue of gold at time was 21.25$ per troy ounce, (12 troy ounce=1lb), gold occurs in seawater to the extent of 4.67x10^17 atom per ton of seawater. (1ton =2000lb) how many cubic kilometers of seawater would have had to be processed to obtain required amt of gold. assem density of seawater is 1.03g/cm*3

PLZ SHOW WORK.

THANKS!!

Answer 1

1)  +2 does not affect the number of neutrons.  It's the overall charge of the atom.  If you think of protons and electrons as individual charges, this is pretty easy.  Each electrons contributes -1 charge, and each proton contributes +1 charge.  So what the +2 is saying is that there are 2 more protons than electrons in the atom.  As for neutrons, do you have the mass number?  If so, #of Neutrons =  Mass Number- # of Protons.  With that info, you can do the problem easily.

2)  First, figure out the weight of gold that equals $28.8 B.  Then, Convert 4.67*10^17 atoms to moles of Gold per ton of sea water.  Convert moles to grams.....convert grams to pounds.  You should have pounds of Gold per ton of seawater.  Then, divide the amount of gold you need by pounds of gold per ton of seawater.  The result is the number of tons of seawater it would take to get $28.8 B.  Convert that to pounds, then grams.  Divide that number by your density, and you'l  have number of cubic centimeters of saltwater.  divide by 10^15 (conversion from cubic centimeters to cubic kilometers), and you'll have your answer.

Answer 2

1. Fe2+ --- Fe is atomic number 26, which is the number of protons by definition. In a neutral element, # protons = # electrons. But with a +2 charge, that means that Fe has lost two electrons (there are two more protons thatn electrons), so # electrons = 26 - 2 = 24. The exact number of neutrons varies. Fe has an average atomic mass of 55.85 amu; the atomic mass = # protons + # neutrons. So # neutrons = atomic mass - # protons = 55.85 - 26 = 29.85. Since we can't have "0.85" neutrons, the 29.85 is a weighted average of all the types of Fe with different numbers of neutrons. All you can say is that Fe has approximatley 30 neutrons (30 is the closest integer to 29.85). The charge on the ion (+2) only affects the number of electrons, not protons or neutrons since they are in the nucleus and the electrons are outside of it.

Apply this same reasoning to Ca2+ and you'll find 20 protons, 18 electrons, and about 20 neutrons.

2. $2.88 x 10^9 x (1 troy oz / $21.25) x (1 lb / 12 troy oz) x (454 g / lb) = 5.13 x 10^9 g Au needed.

4.67 x 10^17 atoms Au / 1 ton seawater x (1 mole Au / 6.02 x 10^23 Au atoms) x (197.0 g Au / 1 mole Au) x (1 ton seawater / 2000 lb seawater) x (1 lb seawater/ 454 g seawater) x (1.03 g seawater / 1 cm^3 seawater) x (100 cm / 1 m)^3 x (1000 m / 1 km)^3 = 1.73 x 10^5 g Au / 1 km^3 seawater

5.13 x 10^9 g Au needed x (1 km^3 seawater / 1.73 x 10^5 g Au) = 2.96 x 10^4 km^3 seawater

Check my math.