Answer:
Most radio waves have wavelengths between 1 mm and 100 km.
A cooling curve shows A. how the temperature of a substance falls as heat is removed.
Explanation:
<em>Radio waves</em> are the longest of all the waves in the electromagnetic spectrum.
Most have wavelengths between 1 mm and 100 km, although there is no upper limit.
Some radio waves have wavelengths of 10 000 km.
A <em>cooling curve</em> (see image below) shows how the temperature of a substance falls as it is cooled.
In Option E., a decrease in temperature would cause an energy <em>loss</em>.
Options B., C., and D. involve the <em>addition of heat</em>.
Answer:
2.35 M
Explanation:
Molarity is mol/L of solution. We have to convert the g to mol and the mL to L. G to mol uses the molar mass of the compound. The molar mass of NaNO₃ is 85.00g/mol.
Then you have to convert mL to L.
Now divide the mol by the L.
Round to the smallest number of significant figures = 2.35M
Answer:
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
Explanation:
The energy carried by electromagnetic radiation is displaced by waves. This energy is not continuous, but is transmitted grouped into small "quanta" of energy called photons. The energy (E) carried by electromagnetic radiation can be measured in Joules (J). Frequency (ν or f) is the number of times a wave oscillates in one second and is measured in cycles / second or hertz (Hz). The frequency is directly proportional to the energy carried by a radiation, according to the equation: E = h.f, (where h is the Planck constant = 6.63 · 10⁻³⁴ J / s).
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. it is expressed in units of length (m). In light and other electromagnetic waves that propagate at the speed of light (c), the frequency would be equal to the speed of light (≈ 3 × 10⁸ m / s) between the wavelength :
So:
In this case, the wavelength is 3.35mm=3.35*10⁻³m and the energy per photon is:
E=5.93*10⁻²³ 
The detector is capturing 3.3*10⁸ photons per second. So, in 1 hour:
E=7.04*10⁻¹¹ 
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
Answer:
3). 1.30 × 10^(24) molecules
Explanation:
From avogadro's law which state that equal volume of all gases at the same temperature and pressure contain the same number of molecules.
We can relate it to this question as;
V₁/n₁ = V₂/n₂
Where;
V₁ is initial volume
n₁ is initial number of molecules
V₂ is final volume
n₂ is final number of molecules
Thus at STP, we have V₁ = V₂ and as such Plugging in the relevant values gives;
5/(1.30 x 10^(24)) = 5/n₂
n₂ = 1.30 x 10^(24) molecules
Models in science help you get the idea of what something looks like that's why your teacher may ask you to draw a diagram to help you remember what the object looks like.
Hope this helps.
