What is the mass in grams of 0.00125 mole of sodium Na=23

0.03g

Explanation:

Given parameters:

Number of moles of Na = 0.00125mole

Unknown:

Mass in grams of Na = ?

Solution:

To find the mass of this substance, we simply multiply the number of moles with the given molar mass of Na.

 Mass of Na  = number of moles x molar mass

 Mass of Na  = 0.00125 x 23   = 0.03g

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.