Religion and science are fundamentally incompatible. They disagree profoundly on how we obtain knowledge of the world. Science is based observation and reasoning from observation. Religion assumes that human beings can access a deeper level of information that is not available by either observation or reason.
Answer:
Explanation:
<u>1. Convert Grams to Moles</u>
Use the molar mass (found on the Periodic Table) to convert from grams to moles.
Use this value as a ratio.
Multiply by the given number of grams.
Flip the ratio so the grams of boron cancel out.
<u>2. Convert Moles to Atoms</u>
We use Avogadro's Number, 6.02*10²³: the number of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case, the particles are atoms of boron.
Multiply by the number of moles we calculated.
The moles of boron cancel.
The original value of grams has 4 significant figures, so our answer should have the same. For the number we calculated, that is the thousandth place.
The 6 tells us to round the 2 to a 3.
25.00 grams of boron is equal to 1.393*10²⁴ atoms.
Nonane (b) has the highest melting point.
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A caveat: I'm assuming that we're dealing with the straight-chain isomers of these alkanes (specifically pentane and nonane). The straight-chain isomer of pentane (<em>n</em>-pentane, CH3-[CH2]3-CH3) has a melting point of -129.8 °C; the straight-chain isomer of nonane (<em>n-</em>nonane, CH3-[CH2]7-CH3) has a melting point of -53.5 °C. The pattern holds as you go down (or up): The more carbon atoms, the higher the melting point. So, in decreasing order of melting points here, you'd have the following: nonane > pentane > butane > ethane.
However, one structural isomer of pentane, neopentane, has a melting point of -16.4 °C, which is <em>higher </em>that the melting point of <em>n</em>-nonane despite neopentane having the same molecular formula as its straight-chain isomer. Of course, you're not to blame for coming up with this question; this is just some extra info to keep in mind.
La química está interviniendo en la industria textil, investigando las maneras de dar mayor resistencia y ligereza a la pieza, hacerla más duradera, más suave, más confortable, más funcional y práctica, tejidos capaces de mutar de manera instantánea en función de la climatología o la reacción al esfuerzo del propio
