capt_yellowbeard

capt_yellowbeard t1_ja9jwg1 wrote

Reply to comment by AnarchistAccipiter in Magnetic pole reversal by Gopokes91

Succinct and well stated.

I’ll add that there is clear alignment “striping” of magnetic particles on the ocean floor. So by drilling different parts of the sea floor one can see which direction north and south were when the magma that makes up the sea floor was deposited. Once it solidifies, however, no further change occurs.

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capt_yellowbeard t1_j1mqnwm wrote

Reply to comment by CanITendTheRabbits in What is the process of breaking apart molecules into the atoms that make it? by TenComet

Oh. I missed distillation in your post. Sorry. In distillation we use the fact that different substances change states at different temperatures in order to separate them (example, separating water from alcohol or the various types of compounds that make up oil (petroleum) into constituent parts like kerosene, diesel, or gasoline. However, generally the substances themselves don’t change chemically.

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capt_yellowbeard t1_j1mppah wrote

Reply to comment by CanITendTheRabbits in What is the process of breaking apart molecules into the atoms that make it? by TenComet

Sure. The things you listed are all state changes - changes between the states of matter - solid, liquid, gas, and (not mentioned in your post) plasma.

Evaporation is liquid to gas. Sublimations is straight from solid to gas (think “what dry ice does”). State changes are driven by a combination of the amount of energy in a substance and pressure. However, when things change states their molecular structures don’t change. Water vapor, liquid water, and solid water (ice) are all the same chemical substance (H2O) just in different states.

For a chemical change, molecules must change. This means that atoms must break and/or create bonds with one another. This happens generally by sharing or exchanging electrons in the outermost shell (called the valence shell) of the atoms. So there will be DIFFERENT molecules after a chemical change then there were at the beginning. Examples of this include burning paper (in which cellulose breaks down to glucose and glucose breaks down to CO2 and H2O) or photosynthesis (which is sort of the reverse chemical reaction) in which plants use CO2 and H2O to make glucose (C6H12O6).

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