Answer:The green growing on the penny of copper and the rust forming on the nail of iron are chemical changes. Boiling away salt water, scraping iron filings from a mixture of sand with a magnet, and breaking a rock with a hammer, are physical changes.
Explanation:
dim? im not so fluent in this but i did research yesterday
Short answer: nitrogen, oxygen, Argon, and
inert gas
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases.
These contribute to climate change.
Answer:

Explanation:
Hello,
In this case, since silver is initially hot as it cools down, the heat it loses is gained by the liquid, which can be thermodynamically represented by:

That in terms of the heat capacities, masses and temperature changes turns out:

Since no phase change is happening. Thus, solving for the heat capacity of the liquid we obtain:

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