Element. It is the simplest form of pure substance. They cannot be broken into anything else by physical or chemical means.
Is this a scienctif question cuss if so it not only helps u with math there’s a lot of subsists like history math English etc....
Answer:
I think it's lead (pb). Hope this helps.
The statement above about "<span>The reduction in the freezing point of a solution is inversely proportional to a molal concentration" is false. It must be directly proportional</span>
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
