Well theres 5 so times 2 equals 10
Answer:
13.5 %
Explanation:
First we<u> calculate the mass of 500 mL of water</u>, using <em>its density</em>:
- 500 mL * 1.00 g/mL = 500 g
Then we <u>calculate the mass percent of potassium sulfate</u>, using the formula:
Mass of Potassium Sulfate / Total Mass * 100%
- 78 g / (78 + 500) g * 100 % = 13.5 %
No. of moles= mass given /mass acquired
.0079=x/238
238×.0079=x
1.88~2
therefore the no. of grams =2g
Iodine has 53 protons. For question 82, the number 127 stands for neutrons plus protons. So the neutron for I-127 is 74. For 83, according to the definition of isotopes, they need to have the same number of protons and different number of neutrons. I-127 and I-131 satisfy these requirements. For 85, the half life of I-131 is 8 days which means after 8 days, only half of sample remains unchanged. So if 80 gram change to 1.25 gram, it goes through 6 half life. So it took 48 days.