Answer: Decreases across the period and increases down the group
Use the formula E=hv, h=plancks constant and v=frequency
use the formula c=v*lambda to find v
the answer will be 2.88*10^-23J
True. Because they are white we know that they reflect light, and thus heat.
Answer:

Explanation:
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In this case, since the reaction for the formation of ammonia is:

We can evidence the 1:2 mole ratio of nitrogen gas to ammonia; therefore, the appropriate stoichiometric setup for the calculation of the moles of the latter turns out to be:

And the result is:

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Maybe her old shoes had soft worn out bottoms and she slips in them. So her new shoes had more grip than her old ones so they kept her from falling.