<u>Answer:</u> The given example is a physical change.
<u>Explanation:</u>
A chemical change is defined as the change in which chemical composition of a substance changes and results in the formation of a new substance. These are usually irreversible process.
A physical change is defined as the change in which only the shape and size of the substance changes and no new substance is formed. Only phase change occurs in these processes. These are usually considered as a reversible change.
For the given example: Moisture in the air forms beads of water on a cold window pane.
This is a physical change because water was initially present in the gaseous state (Moisture in the air) and when it is coming in contact with the cold window pane, the gaseous state of water gets converted into a liquid state.
Hence, the given example is a physical change.
Multiply amount in grams by the relative atomic mass of magnesium then multiply by avagodro constant (6.02*10^23)
Why is hydrogen a “cleaner” fuel source than gasoline?
hydrogen is natural created and in the air already, gas is a fossil fuel and is killing the Ozone layer. carbon dioxide is a poison and can really harm us and the world.
this paragraph basically explains the question
Compared to the carbon dioxide that is produced when we burn gasoline, ethanol, and other carbon-containing fuels, the water produced by burning hydrogen has a less harmful effect on Earth’s climate. If we can power our cars with hydrogen without producing carbon dioxide, then why don’t more vehicles use hydrogen fuel? Unfortunately, the technology needed to use hydrogen as a fuel is expensive, and storing hydrogen fuel can be difficult. Also, the most common way of getting pure hydrogen is by separating it from substances that contain carbon—so although burning hydrogen fuel does less harm to Earth’s climate than burning carbon-containing fuels, the production of hydrogen fuel is still a problem for scientists trying to reduce climate change.