Answer:
I think that it is A I am sorry if I am wrong
Explanation:
The density at 1,291 km from the surface of the planet is
[ (1,291 - planet's radius)/(planet's radius) ] ^ some power .
Answer:
a) the atomic number is 15
b) the mass number is 15+16 = 31
c) element is phosphorus
d)Group 15 period 3
First one I believe is 5.
2nd is given already
3rd is 1
4th is 2
