An Adam has 18 protons and 8 valance electrons. which which statement would best identify this element 1.the element is highly reactive with eight electrons in its outer shell

2. The element has an atomic mass of eight

3. The element is “happy” or stable because it outer energy level is filled

4.the element is a metal

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

i'm assuming that the correct answer is indeed the first one/ "a"..

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole