1) Left up: a chemical change. We can see new substance (red-blue) is formed from one blue and one red atom.
In chemical change new substances are formed, the atoms are rearranged and the reaction is followed by an energy change.
2) Left down: a chemical change. We can see new substance (red-blue) is formed from two blue and one red atoms.
3) MIddle: a physical change. There is no new substance. Bonds are not broken.
4) Right up: a chemical change. Bonds are broken.
5) Right down: a physical change. Change of state of matter.
Answer:
Fossil B
Explanation:
Fossil B is older because it's later is at the bottom
Chlorine is used in swimming pools to kill unwanted bacteria and keep swimmers safe from infections and disease from the water. While there isn't enough chlorine in swimming pools to cause permanent damage, it can leave your hair dry and your skin irritated and red.
The answer is B. Acid turns blue litmus paper to red
Answer:
18.9 moles of MgCl2 = 17.834 kg of MgCl2
Explanation:
The molecular weight of MgCl is 80.0 g/mol . So, to convert the given mole amount to grams, multiply this by this number, which is constant for all compounds with a specific composition (mass fraction).
Considering the original question was in the context of chemistry, I wanted to make it seem formal and more educational too. Hopefully that worked!
EDIT: Came up with some text around what happens inside cells that would have made it better if someone just had an issue converting units, but I doubt my answer will be accepted >.<
