I think you mean ionic bond and not conic bond. The pair of elements that form an ionic bond are barium and chlorine.
Keeping the masses of the objects unchanged, if the distance between the objects is halved, then the magnitude of gravitational force between them will become. Hope this helps please mark brainliest :)
The most concentrated solution is b
Answer:
0.136g
Explanation:
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?

Initial mole of Co(NO3)2 

Mole of Co(NO3)2 in final solution

Mole of NO3- in final solution = 2 x Mole of Co(NO3)2

Mass of NO3- in final solution is mole x Molar mass of NO3
