In, 1937 Lawrence, in operating his cyclotron, bombarded a molybdenum-96 foil with deuterium ions (2h), producing for the first time an element not found in nature. He was initially unaware that the radioactivity produced by the "bombarded foil" was not from molybdenum but from a new, artificial element. It was his cooperation with Italian-American physicist <span>Emilio Segrè </span>that allowed the new element to be discovered. The answer is Technetium: Tc
The average atomic mass of an element can be determined by multiplying the individual masses of the isotopes with their respective relative abundances, and adding them.
Average atomic mass of Br = 158 amu(0.2569) + 160 amu(0.4999) + 162 amu(0.2431)
Average atomic mass = 159.96 amu
As described in the problem, the relative abundance for Br-79 is 25.69%. This is because 2 atoms of Br is equal to 79*2 = 158 amu. Similarly, the relative abundance of Br-81 is 81*2 = 162, which is 24.31%.
Answer:
it is made up of rays of varying frequencies
Handle of frying pan would be a
good use for a nonmetal. A nonmetal is neither a good thermal insulator nor a
good electrical conductor. Because it is neither, it can be use as a semiconductor.
It does not absorb heat that much that is why it is best in insulating.
Answer:
molarity= 0.238 mol L-
Explanation:
The idea here is that you need to use the fact that all the moles of sodium phosphate that you dissolve to make this solution will dissociate to produce sodium cations to calculate the concentration of the sodium cations.
Na 3 PO 4 (aq) → Na + (aq) + PO3−4 (aq)
Use the molar mass of sodium phosphate to calculate the number of moles of salt used to make this solution.
3.25g⋅1 mole N 3PO4 163.9g = 0.01983 moles Na3 PO 4
Now, notice that every
1 mole of sodium phosphate that you dissolve in water dissociates to produce
3bmoles of sodium cations in aqueous solution.
