I believe the answer is "After adding two substances together a new order is detected" because nearly all of the other answers suggest a chemical change has taken place. The reason I say "almost" is because answer two and four results in bubbles forming so the answer cannot be both. The only one to not clearly show a chemical change has occurred is the last answer.
Answer:
The main source of energy is the sun. The sun has a big part in the water cycle because it turns the water into water vapor. This cause the water cycle to start over again once it rains. Therefore, making the sun ne of the biggest parts in the water cycle.
Bond Order = [Σ (bonding e-) - Σ (antibonding e-)]/2
<span>Be2 = 4e = σ1(2e) σ2*(2e) σ3(0) π1(0) π2*(0) σ4*(0) bo = 0 </span>
<span>[Be2]+ = 3e = σ1(2e) σ2*(1e) σ3(0) π1(0) π2*(0) σ4*(0) bo = 0.5 </span>
<span>[Be2]+ would be more likely to exist since it has a bond order of 0.5 whereas Be2 has zero bond order</span>
Answer: Ice melting into water is an example. Or iron melting into liquid iron.
Answer: Yes- Rusting is an oxidation reaction. The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust. Iron and steel rust when they come into contact with water and oxygen – both are needed for rusting to occur. Rusting is an example of a chemical change. A chemical property describes the ability of a substance to undergo a specific chemical change. A chemical property of iron is that it is capable of combining with oxygen to form iron oxide, the chemical name of rust.
Hope this helps.... Stay safe and have a Merry Christmas!!!!!!!!!!!! :D