Answer:
Number of moles (n)=
molecular weight
weight
Weight=n×Molecular weight
=0.5×14
Mass=7g
Using Avagadro’s number (1 mole = 6.022 x 10^23 molecules) you can take the moles given
2.5 x (6.022 x 10^23) to get 1.5055x10^24 molecules.
You’re being asked to write the noble gas notation for the elements. Basically what you do is write the noble gas before the element in brackets and then continue the electron configuration from there (it’s kind of like a short cut). Heres an example: the noble gas notation for Cs (cesium) is: [Xe] 6s2. Also for the expected last terms of the element, you basically just write the last term of the electron configuration. For example, the last term of the electron configuration for Cl (Chlorine) is “3p5” I’ll attach a picture of the periodic table but with the electron configuration format over it to help you.
