The electons are in the atmosphere
Answer:

Explanation:
Atomic radius is the measurement from the nucleus to the outer edge of the electron cloud.
As you go down a group (vertically) the atomic radius increases because more electron shells are added. As you go across a period horizontally, the atomic radius decreases.
If we look at the halogens group (17), we see they follow this order from top to bottom:
F - Fluorine
Cl - Chlorine
Br - Bromine
I - Iodine
Since it increases down the group, iodine must have the largest atomic radius.
Answer:
Second Earth's Atmosphere
The second atmosphere, which was the first to remain with the earth, was created by volcanic outgassing and comet ice. There was a lot of water vapor, carbon dioxide, phosphorus, and methane in this atmosphere, but absolutely no oxygen.
Explanation:
The outer electron in magnesium is excited by absorbing the heat energy from the N=1 stage to higher energy levels when it starts to drop back down to the N=2 level it losses energy in the form of visible light this is part of the Balmer series
hope that helps
Answer: Mars
Explanation: The planet of Mars is the only planet of all that is terrestrial. Jupiter, Saturn and Neptune are all Jovian Planets. The answer to the question is Mars. Hope this answer helps you!