If you do not wait until the crucible is at room temperature, its density will vary constantly until it reaches this temperature, since density is a property that varies with temperature. For the above reason, weighing a hot crucible will not allow the measurement of a constant weight on the balance, since <u>the weight of the object will be constantly changing, which will not allow a constant reading.</u>
They are both important cell signaling molecules and both of them contain phosphate groups.
Answer:

Explanation:
Hello,
In this case, the Boyle's is mathematically defined via:

Which stands for an inversely proportional relationship between volume and pressure, it means the higher the volume the lower the pressure and vice versa. In such a way, since the volume is decreased to one quarter, we can write:

We can compute the new pressure:

Which means the pressure is increased by a factor of four.
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The correct answer is d) methane (

)
The other options are elements.
Well I'm sure many a time you've seen on some science experiment someone wrap a copper wire around a nail well thats generally the idea for electromagnets you get a solid piece of iron which is the only metal that is magnetic and you wrap a copper wire around it and the idea is to make two opposing magnetic poles by aligning the molecules with a electrical charge (a battery) so now with all three pieces assembles you have a copper wire attached to two sides of a battery and wrapped around a nail