Given:3.40g sample of the steel used to produce 250.0 mLSolution containing Cr2O72−
Assuming all the Cr is contained in the BaCrO4 at the end.
(0.145 g BaCrO4) / (253.3216 g BaCrO4/mol) x (250.0 mL / 10.0 mL) x (1 mol Cr / 1 mol BaCrO4) x (51.99616 g Cr/mol / (3.40 g) = 0.219 = 21.9% Cr
Answer:
7 is the mass number of li and 3 is the atomic number
a 3
b 7
c 3
d 4
Carbon -13 has 7 neutrons and carbon -12 has six neutrons. Carbon -12 is the most common isotope of Carbon. Carbon -14 is radioactive and vary rare. The symbols for the isotopes of Carbon atoms shown here indicate they each have six protons but mass numbers of 14, 13, and 12. Hope this helps. :)
<span>The following is the role of NaCl and EDTA in DNA isolation, hope it helps:
NaCl provides Na+ ions that will block negative charge from phosphates on DNA.
Negatively charged phosphates on DNA cause molecules to repel each other. The Na+ ions will form an ionic bond with the negatively charged phosphates on the DNA, neutralizing the negative charges and allowing the DNA molecules to come together.</span>