Answer:
D
Explanation:
If the atom is neutral, the sum of the core and valence electrons is the same as the number of protons, which is the atomic number of the element. So if the sum of the core and valence electrons in a neutral atom equals 25 , that is the number of protons in the atomic nucleus, and the atomic number of the element.
Al4C3 + 12H2O = 4Al(OH)3↓ + 3CH4
It’s soluble in NaOH, NaH