The elements that fill the d orbitals on the periodic table are called transition metals.
the formula of the compound that is formed between chlorine and calcium is CaCl2
explanation
chlorine (non metal) react with Calcium ( a metal) to form an ionic compound CaCl2
Ionic compound is formed when metal loses electrons to form cation ( a positively charged ion) while non metal gains electrons to form anion ( a negatively charged ion)
An ionic compound is formed when calcium metal(Ca) loses two electron to form Ca2+ cation , while 2 chlorine atom gain one electron each to form cl- anions.
- when writing down the formula of ionic compound cation symbol is written first followed by anion symbol.
Therefore the formula of ionic compound formed between chlorine and calcium is CaCl2
B. This looks like ice turning to water then to steam
The most common reaction that causes spoilage isn't a reaction at all. Molds and Bacteria are attracted to the easily found presence of water in the fruit. They find a natural place to reproduce and what they do causes spoilage.
Very few sources talk about the chemical changes that take place. If you put fruit in a refrigerator it slows the spoiling process down. That means that the chemical reaction has to be endothermic (it requires heat to occur)
The process of spoilage is speeded up by bananas for example, giving up Ethylene gas. You do not want to put a banana with tomatoes, because tomatoes are very sensitive to Ethylene. (It's OK to eat them together. They make a terrific salad. Yum).
I cannot find a definitive source that connects all this together, but the conduct of the fruit in refrigerators confirms what I am saying.
Spoilage is a very complex reaction and interaction with the environment. I have given you a hint of what happens but you should search it out to convince yourself of the outcome.
D. An animal decaying after it dies seem to be the right answer hopefully.