2+ charge electrons of course
For example, at sea level the atmospheric pressure is 760 mm Hg<span> (also expressed as 760 torr, 101325 Pa, 101.3 kPa, 1013.25 mbar or 14.696 psi) and pure </span>water<span> boils at 100°C. However, in Calgary (approx. 1050m above sea level) the atmospheric pressure is approximately 670 </span>mm Hg<span>, and </span>water<span> boils at about 96.6°C.</span>
The scientific notation should specific the significant digits. So it to write like x.xx * 10 ^ x. So the answer is 6.421 * 10 ^3.