Each pure element has certain chemical properties, a specific atomic arrangement and a specific crystalline structure that distinguish this pure element from other elements.
On the other hand, the mass of any substance/object depends on the AMOUNT or the QUANTITY of matter in the object.
Based on the above, three objects made of pure iron would have:
Different masses
Same arrangement of atoms
Same crystal structure
Same chemical properties
Comparing the above to the given choices, we would find that the best choice is:
b. They have the same chemical properties
The average speed is 8 miles
I have no idea what lesson you're talking about, but I am multilingual so I'm sure my answer can suffice for the small amount of details.
One advantage of being bilingual as a child is that, when faced with text written in a different language nobody else but you understands, you can save everyone's butt from taking out inaccurate translators for that text.
The disadvantage that follows that is the fact that people will now recognize you as that one dude that speaks every language, even if you don't. So, now, you have everybody coming up to you to translate everything they don't understand.
Another advantage is that you can read something everyone else would find disturbing (like, my graphic horror/action stories) without anybody understanding it because it's in another language.
The disadvantage that follows is that they're almost always going to be nosy brats and asking what every word means.
The last advantage I'll list is that you can get away with saying stuff. Like, "man, that woman must be on something", or, "darned drunkards", without starting up a fight with them, because, really, who's going to understand Thai way over in America? (I honestly wouldn't recommend risking it, though. Speaking of which...)
The last disadvantage here is the fact that you won't know who speaks these languages around you. For all you know, your best friend had understood every comment about the loony across the street and simply chose not to comment on it.
So, for the final conclusion, knowing different languages is great and all, but it's not that great.
Electric current is the movement of the electrons caused by potential
difference. For example, in a circuit, the electrons in the bulb will not move
without the potential difference or voltage. When there is voltage, electric
current occurs because there is a driving force for the electrons in the wire
to move.