They are both sources of power for objects that people use.
ELECTRON CONFIGURATION
Highest occupied energy level of an element
equal to the period
for example, the highest occupied energy level of He is 1, Be is 2, Al is 3, Ca is 4, and Sn is 5
Density is equal to mass divided by volume so the densest object will be the object that has the largest mass in the smallest area.
In this case object A is the densest with a density of 10g/cm^3.
I hope this helps. Let me know if anything is unclear.
Answer:
Co(cobalt) is the answer
Explanation:
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.