You can tell that the atom is in the excited state because:
- Electron configuration should follow the 2-8-8-2 rule, meaning that the inner shell should be filled before the next shell can start holding electrons.
- Instead of the atom's electron configuration being in the ground state at 2-8-8-1, electrons from the second shell have jumped to the third.
The last one 1) exothermic; 2) exothermic
214.0560
+ 9.3456
=223.4016
do you mean polymers or organic compounds?
13
Al
Aluminum
Atomic mass 26.982