Answer:
(A) The shorter the wavelength, the more total energy the wave contains.
(B) The longer the wavelength, the less total energy the wave contains.
Explanation:
The wavelength (λ), frequency (f) and energy (E) are interrelated. This relationship between them is represented in the following equations:
λ = v/f and E = hf
Where;
λ = wavelength (m)
f = frequency (Hz)
E = energy (Joules)
v and h represents speed of light and Planck's constants respectively.
Combining both equations, E = hc/λ
This equation shows that ENERGY (E) is directly proportional to the frequency (f) but inversely proportional to the wavelength (λ). This means that "the shorter the wavelength, the more total energy a wave contains" and vice versa.
However, the higher the frequency, the more the total energy the wave contains and vice versa.
Answer: 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, 
Explanation:
The reaction equation for given reaction is as follows.

Here, 1 mole of
reacts with 3 moles of
.
As mass of chromium (III) oxide is given as 76 g and molar mass of chromium (III) oxide
is 152 g/mol.
Number of moles is the mass of substance divided by its molar mass. So, moles of
is calculated as follows.

Now, moles of
.given by 0.5 mol of
is calculated as follows.

As molar mass of
is 2.016 g/mol. Therefore, mass of
is calculated as follows.

Thus, we can conclude that 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide,
.
Answer:
Double replacement is the answer