Dark colored moths survived better in the Industrial Revolution because their dark color helped them camouflage in soot. When the industrial revolution ended there wasn't as much soot, so the light colored moths now had a better chance of survival.
Answer : The correct answer is Option D.
Explanation:
Ores are defined as natural occurring substance from which metals and another mineral are extracted.
Bauxite is primary ore of an aluminium metal. it doesn't have definite or specific chemical composition. This is because it contains mixture of hydrous aluminum oxide
, aluminum hydroxides
, insoluble materials like hematite, quartz ,geothite ,magnetite etc.
From the given options the most appropriate statement which is correct about the bauxite is 'It does not have a definite chemical composition'.
Hence, the correct option Is (D).
TLDR: The energy was being used simply to heat the substance up.
Whenever something melts, it performs what is called a "phase transition", where the state of matter moves from one thing to something else. You can see this in your iced drink at lunch; as the ice in the cup of liquid heats up, it reaches a point where it will eventually "change phase", or melt. The same can be achieved if you heat up that water enough, like if you're cooking; when you boil eggs, the water has so much thermal energy it can "change phase" and become a gas!
However, water doesn't randomly become a boiling gas, it has to heat up for a while before it reaches that temperature. For a real-life example, the next time you cook something, hold you hand above the water before it starts boiling. You'll see that that water has quite a high temperature despite not boiling.
There's a lot of more complex chemistry to describe this phenomena, such as the relationship between the temperature, pressure, and what is called the "vapor pressure" of a liquid when describing phase changes, but for now just focus on the heating effect. When ice melts, it doesn't seem like its heating up, but it is. The ice absorbs energy from its surroundings (the warmer water), thus heating up the ice and cooling down the water. Similarly, the bunsen burner serves to heat up things in the lab, so before the solid melts in this case it was simply heating up the solid to the point that it <u>could</u> melt.
Hope this helps!
Answer :
Option A) 2.00 eV
Explanation : The conversion of J to eV is done with the following formula;
Here, we have the value of particle in terms of Joules which is 3.2 X
So, on substituting we get,
= 3.2 X
X
= 1.99 eV so, it can be rounded off to 2.00 eV.
