Answer:
1.76 g/mL
Explanation:
You need to find the volume. You can do this by subtracting the volume of the water and the rock by the volume of the water.
72.7 mL - 50 mL = 22.7 mL
Now that you have volume, divide the mass by the volume to find the density.
39.943 g/22.7 mL = 1.76 g/mL
<span>An exothermic reaction is one in which there is the production of heat whereas an endothermic reaction is one in which heat is absorbed. For the choices above, the answer would be letter B. Ice melting in water and an ice pack turning cold absorbs heat which is why it is an endothermic reaction. Exploding fireworks and gasoline burning gives off heat which is why it is an exothermic reaction.</span>
Remark
The short Answer is 6. That's why the ion has a charge of minus 2. Oxygen is doing it's best to have its outer ring have 8 electrons which is the number of outer electrons contained in the outer ring of the Noble Gas Neon.
Answer 6.