You discover that an atom of an unknown element has 54 protons, Identify the element and explain how you know the identity is correct
Explain whether the unknown element is more or less reactive than an atom of an element that has 30 protons,
Identify an element that would have very similar chemical properties to the unknown element and explain why its chemical properties would be similar

Xenon, because the amount of protons=the atomic number, and Xenon’s atomic number is 54. Some elements with similar chemical properties would be Neon, Helium, Argon, Krypton, Nitrogen, etc because they are all in the period #18, which means they have similar properties. They are all noble gases. Hope this helps :)

  the volume of  0.220 m k2s    solution  required  to  completely  react with 175 ml  of 0.115m co(no3)2  calculate the moles  of co(no3)2 =  molarity x volume/1000175 x0.115/1000= 0.02  moleswrite  the reacting  equationk2s(aq)  +  co(no3)2  = 2 kno3(aq)  + cos(s)by  use  of mole ratio between k2s to co(no3)2 which  is  1: 1 the moles of k2s is therefore = 175  x0.115/1000= 0.02  molesvolume = moles/molarity=0.02/0.22=0.09  ml  of k2s