Answer:
All the members of a group of elements have the same number of valence electrons and similar chemical properties.
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior.
Answer:
The speed of light is the speed at which light travels. No, an object cannot move at the speed of light.
Explanation:
The speed of light is 186,000 miles per second. An object with mass cannot move at the speed of light since it would take an infinite amount of energy to achieve that velocity, since only massless particles can travel at the speed of light. Also, you would have to factor in air friction, meaning even if an object were to reach such high speeds, it would instantly disintegrate.
Answer:
See explanation.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to firstly recall the electron configuration of hydrogen:

To realize that the principal quantum number is 1, the angular is 0 as well as the magnetic one; therefore we infer that all the given n's are not allowed, just l=0 is allowed as well as ml=0 yet the rest, are not allowed.
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