A physical property is what a substance is like; it's directly observable. On the other hand, a chemical property is how a substance behaves; its reactivity.
Examples of a physical property are: color, texture, boiling point, freezing point, and melting point.
Examples of a chemical property are: flammability, combustion, and formation of a precipitate.
Hi there! Air and sunlight can definitely be reused. Those are abundant and renewable resources. Therefore, A and D are eliminated. There is a limited amount of water, however, it's impossible to run out of it to the point that there's no more on Earth. C is out. The only answer choice that makes sense is coal, because it's a nonrenewable resource, and it takes millions of years to make more of. It's a fossil fuel, so once we use them up, we can't get anymore during our lives. The answer is B: coal.
There are many kinds of pyroclastic material ejected during a volcanic eruption. Ash is the most common pyroclastic rock material ejected during an eruption. Volcanic ash is so fine that it can be blown into the atmosphere and picked up by the jet stream where it can circle the Earth for several years.
ANSWER
Power stroke
EXPLANATION
At the power stroke stage, the piston is forced to move down by the expanding gases as both intake valve and exhaust valve are closed.
A spark from the spark plug contributes to ignition of the compressed fuel air mixture to released energy to perform work.
Fe needs to have a positive charge of +3 to balance out -3 Cl