Problem 1: You have a rock with a volume of 15cm3 and a mass of 45 g. What is its density? Density is mass divided by volume, so that the density is 45 g divided by 15cm3, which is 3.0 g/cm3
Explanation: The top question answer is 3.00 g/cm3 .... I hope this helps!!! (PLEASE RATE ME AS BRAINLY)
I'm pretty sure the answer is the first one. The fact that it doesn't have a full valence shell means that electrons from other atoms can react and bond with the sodium atom. Hope this helps x