Answer:
A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Energy is always required for bond formation because when a chemical reaction occurs, either molecular bonds are broken or other bonds are formed to make different molecules. Energy is released during bond formation and is an exothermic process because bond formation represents a stable configuration and the energy lost is released as heat energy that makes it more stable. Breaking bonds takes energy and is an endothermic reaction because energy is absorbed to break bonds.
Hope that helps. x
Answer:
Both are at the side of the spectrum that has the lowest frequency.
Explanation:
i took the test
Hey there!
I assume you want this equation balanced.
Al₂(SO₄)₃ + Ca(OH)₂ → Al(OH)₃ + CaSO₄
Let's start by balancing the polyatomic ions, starting with SO₄.
There are 3 on the left and 1 on the right, so let's add a coefficient of 3 in front of the CaSO₄.
Al₂(SO₄)₃ + Ca(OH)₂ → Al(OH)₃ + 3CaSO₄
Now let's balance the polyatomic ion OH.
There are 2 on the left and 3 on the right, so let's put a coefficient of 3 in front of Ca(OH)₂ and a coefficient of 2 in front of Al(OH)₃.
Al₂(SO₄)₃ + 3Ca(OH)₂ → 2Al(OH)₃ + 3CaSO₄
Now let's balance Al.
There are 2 on the left and 2 on the right, so Al is already balanced.
Lastly, let's balance Ca.
There are 3 on the left and 3 on the right, so Ca is already balanced.
This means we're done! Here's the final balanced equation:
Al₂(SO₄)₃ + 3Ca(OH)₂ → 2Al(OH)₃ + 3CaSO₄
Hope this helps!
Hey there!
Chemical changes are changes in object's chemical compounds and chemical compositions, and often can't be reversed.
Here's an example:
If you have a piece of paper and you happen to burn it, that can't be reversed.
In other words, it can't be "un-burned". Nothing can restore it to its previous state.
Hopefully this helped!
A polyatomic ion<span>, as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex</span>