The answer to both is D. Here's why:
For the first, whenever motion changes in a magnetic field, it causes electrons to move. Electricity, which is needed to power a lightbulb, is just a term for movement of these electrons. Electrons aren't created, they're always there in the wire. It's just that the permanent magnet gets them to move, which produces electricity.
For the second, it is very similar to the first. A magnet won't cause any electric current at rest, it always requires motion in order to produce an electric current. If you keep both of those in mind, it should help in the future. Hope this helps!
Answer:
all 4 of the middle ones are part of the nucleus
Answer : The molecular weight of this compound is 891.10 g/mol
Explanation : Given,
Mass of compound = 12.70 g
Mass of ethanol = 216.5 g
Formula used :

where,
= change in freezing point
= temperature of pure ethanol = 
= temperature of solution = 
= freezing point constant of ethanol = 
i = van't hoff factor = 1 (for non-electrolyte)
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of this compound is 891.10 g/mol
Brass is an alloy, or a combination of two (or more) metals.
Answer:
CaCl2 + H2O Ca2+(aq) + 2Cl-(aq)
Explanation:
CaCl2 + H2O Ca2+(aq) + 2Cl-(aq)
When CaCl2 is dissolved in H2O (water) it will dissociate (dissolve) into Ca+2 and Cl- ions.
The dissolution of calcium chloride is an exothermic process.