Answer: a
Explanation: a naturally occurring, inorganic solid that has a crystal shape and a definite chemical composition" is the one among the following choices given in the question that is the correct definition of minerals. The correct option among all the options that are given in the question is the first option. I hope it helps you.
Pb (lead) is in the 6th period
(please give brainliest if this helped you)
B) energy and wavelength decrease
C) energy decreases, wavelength increases
D) energy increases, wavelength decreases
When the frequency of the waves increases, its energy increases, while the wavelength decreases.
• A travelling disturbance, which mediates energy from one place to another is known as a wave.
• The tendency to do work or cause a change is known as the energy.
• Waves can be determined with the help of frequency and wavelength.
• In a given unit of time, the number of complete wavelengths is known as frequency.
• With the increase of the size of wavelengths, its energy and frequencydecreases.
• There are two basic kind of waves, that is, electromagnetic and mechanical waves.
• The waves, which can travel through a medium or a vacuum is known as the electromagnetic waves.
• The waves with long wavelengths comprise less energy than waves with short wavelengths.
Thus, correct answer is option d, that is, energy increases, wavelength decreases.
To know more about:
As the frequency is how many waves pass a fixed point in certain amount of times. This means that the waves get closer together and, therefore, the wavelength decreases. It also means that the wave has more energy.
Answer: D) Energy increases, wavelength decreases
4PCl5(g) → P4(s) + 10Cl 2(g) ΔH = 3438 kJ
The value of ΔH will be 249.75 KJ.
To obtain the reaction :
PCl5(g) → PCl3(g) + Cl2(g)
We have to add the given reactions and then divide it by 4.
(i) adding the reactions
P4(s) + 6Cl2(g) → 4PCl3(g) ΔH = -2439 kJ
4PCl5(g) → P4(s) + 10Cl 2(g) ΔH = 3438 kJ
we get:
4PCl5(g) → 4PCl3(g) + 4Cl2(g), ΔH = 3438 - 2439
(ii) dviding by 4
PCl5(g) → PCl3(g) + Cl2(g) , ΔH = (3438 - 2439)/4
ΔH = 249.75 kJ is the required enthapy.
Learn more about enthalpy:
Answer:
The value of for the desired reaction will be 249.75 KJ.
Explanation:
The desired reaction is shown below
The desired reaction can be obtained by adding the given reactions and then dividing both sides by 4.
Net Enthalpy change for the desired reaction