hydrogen is the lightest element in the periodic table
Atomic Numbers are the number of protons within the nucleus,
which is 58 here.
Atomic Number=58
Mass Number is the sum of the protons and neutrons in the nucleus,
=58+82
Mass Number=140
Periodic symbol of this isotope is entirely dependent on the number of protons, 58, which corresponds to the element Cerium, abbreviated as Ce in the periodic table.
Periodic Symbol=Ce
Answer:
The solution is 50 %wt
Explanation:
50% wt is a sort of concentration and means, that 50 g of solute (in this case, the potassium bromide) dissolved in 100 g of water.
It is the same to say, that there are 50g of KBr for every 100g of H₂O
The third is one: controlled burn
