Answer: I would choose the fourth
Explanation: b/c group 18 on the periodic table have the most stable valence electrons (the # of valence electrons are full and no side outweighs another). At least that’s what my teacher last year said.
Stuff about the earth and tectonic plates, and about space and stuff.
Answer: 1 mole Kr
Explanation: solution
83.80g Kr x 1mole Kr / 84 g Kr
= 0.997 or approximately 1 mole Kr
fourth period
The third period is similar to the second, except the 3s and 3p sublevels are being filled. Because the 3d sublevel does not fill until after the 4s sublevel, the fourth period contains 18 elements, due to the 10 additional electrons that can be accommodated by the 3d orbitals.
I believe that the ice cube, being that it still has almost all of its properties, would still have a mass of 25 g after melting
