Since this element has 50 electrons you know that it has 50 protons. The number of proton= the atomic number. Atomic number 50 is tin. The atomic symbol for tin is Sn and the weight is 120. So this is the tin 120 isotope
7.5 M is the concentration of 60 ml of H3PO4 if it is neutralized by 225 ml of 2 M Ba(OH)2.
Explanation:
Data given:
volume of phosphoric acid, Vacid =60 ml
volume of barium hydroxide, Vbase = 225 ml
molarity of barium hydroxide, Mbase = 2M
Molarity of phosphoric acid, Macid =?
the formula for titration is used as:
Macid x Vacid = Mbase x Vbase
rearranging the equation to get Macid
Macid = 
Macid =
Macid = 7.5 M
the concentration of the phosphoric acid is 7.5 M and the volume is 60 ml. Thus 7.5 M solution of phosphoric acid is used to neutralize the barium hydroxide solution of 2M.
Unstable, radioactive atom emits alpha and gamma ray to transform into a stable atom.
Emitting an alpha particle, decreases the mass number by four and atomic number by two.
Emitting gamma ray reduces the excess energy of the radioactive atom.
The correct answer would be the first option. Material A having a smaller latent heat of fusion would mean that it will take only less energy to phase change into the liquid phase. Latent of heat of fusion is the amount of energy needed of a substance to phase change from solid to liquid or liquid to solid.