1. A
2. D
3. C
4. B
Hope this helps.
Explanation:
1=2 atoms
2=4-n where n is the number of bonds to that carbon
3=10
4=2
Both acid and base
Because
Acid + Base → Water + Salt
Explanation:
a) Bohr model is perfect for atoms that have single electron and fortunately both Be3+ ion and H atom have one electron so, Bohr model can easily and accurately applied to predict the spectrum of Be3+ and H atom.
b) The energy of an atom in Bohr model is given by

the values of z for H atom and Be3+ ion are 1 and 4 respectively. Hence, energy of atoms would be different for both atoms. Hence, line spectra to be identical is not possible.