Question

Why do the elements of period 4 start a new cycle of properties after the element argon? Select all that apply.

1. The electrons in the outermost energy level are primarily responsible for the properties of an element.
2. The n = 3 energy level of argon is complete.
3. Additional electrons after argon begin to fill a sublevel of the n = 4 energy level.
4. All the energy levels of period 4 elements are less than period 3 because the amount of energy between energy levels decrease with distance from the nucleus.

Answer 1

3. After 3p orbitals are filled, 4s starts before 3d will be filled.

Answer 2

I think there is another one, because I had that one. I am getting 3 out of 4.

Answer 3

4 should also be correct

Answer 4

I guess it is not.

Answer 5

try 2 and 3