Hi, I believe this question is asking what charge Phosphorus will have when it forms an ion. If that is the case, you will see that it based on the column it is in, neutral Phosphorus has 5 valence electrons. When it becomes an ion (has 8 valence electrons), it will GAIN three electrons. Meaning, we can predict that Phosphorus will have a 3- charge when it becomes an ion.
Density is too do with how much of a mass is condensed or concentrated in a unit of volume: Density = Mass / Volume
So applying it to the given data:
10/2 = 5
Density is 5 g/ml
[ml is usually the equivalent of one cm³, so it could also be written as 5 g/cm³ I guess]
Answer: 2, 4
Explanation:
Carbon varies, so it can have either 2 or 4 electrons
I think the correct answer from the choices listed above is the third option. The element that will have similar chemical properties to francium would be rubidium since they are in the same column. <span>Groups of </span>elements in the same<span> column have similar </span>chemical <span>and physical </span>properties<span>, reflecting the periodic law.</span>
