Answer: Option (D) is the correct answer.
Explanation:
Valence shell is the shell present on the outermost core of an atom and electrons present in the valence shell are known as valence electrons.
If an atom has completely filled valence shell then it means the atom is not reactive in nature because it is already stable.
But when an atom has less than eight electrons in its valence shell then it means to attain stability the atom will readily attract electrons towards itself.
As the given element 1 has 8 electrons in its valence shell. Hence, it is not reactive in nature but element 2 has 6 valence electrons. So, in order to attain stability element 2 will readily attract 2 electrons from a donor atom.
Thus, we can conclude that element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.
When two atoms of Hydrogen combine together, or fuse, they make an atom of Helium.
A. about 14 days
EXPLANATION
It takes 27.5 days for the moon to orbit the Earth, so a solar eclipse and a lunar eclipse can never take place less than about two weeks apart.
For solar eclipse, the moon must be in between Sun and Earth. And every one knows full moon and new moon can't happen same day.
