Which phrase best describes this reaction? (1.) endothermic with ΔH = +1640 kJ (2.) endothermic with ΔH = -1640 kJ (3.) exothermic with ΔH = +1640 kJ (4.) exothermic with ΔH = -1640 kJ

8

explanation:

each principal energy level above the first contains one s orbital and three p orbitals. a set of three p orbitals, called the p sublevel, can hold a maximum of six electrons. therefore, the second level can contain a maximum of eight electrons - that is, two in the s orbital and 6 in the three p orbitals.

mark brainliest and have a great day!

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons