Answer:
The atoms in the first period have electrons in 1 energy level. The atoms in the second period have electrons in 2 energy levels. The atoms in the third period have electrons in 3 energy levels. The atoms in the fourth period have electrons in 4 energy levels.
Since nickles atomicnumber is 28, that means it has 28 protons, which are positively charged. To cancel out the positive charge and make it nuetral, there isalso 28 electrons which are negatively charged.
Nickel has 31 neutrons because an atoms mass is the number of protons + neutrons. The # of protons is 28. The mass # is 59. So, there are 31 neutrons.
Answer:
I think it would be:
NaCO3 (s)-->Na2O (s) + CO2 (g)
