C, it prevents the Earth from ultraviolet radiation and other harmful substances from space
Wavelength is the distance of one frequency wave peak to the other and
is most commonly associated with the electromagnetic spectrum.[1]
Calculating wavelength is dependent upon the information you are given.
If you know the speed and frequency of the wave, you can use the basic
formula for wavelength. If you want to determine the wavelength of light
given the specific energy of a photon, you would use the energy
equation. Calculating wavelength is easy as long as you know the correct
equation.
Halogens is defined as the group of 7 periodic table. As, every periodic table contains 7 valence electrons and they only need 1 more to complete an outer shell, that is why they are extremely reactive. And according to the law that recurring patterns of the properties of elements arise when they are arranged in order of increasing atomic number. As the halogen all act very similarly with each other in chemical reaction, it is true.
Answer: d) -705.55 kJ
Explanation:
Heat of reaction is the change of enthalpy during a chemical reaction with all substances in their standard states.

Reversing the reaction, changes the sign of 


On multiplying the reaction by
, enthalpy gets half:


Thus the enthalpy change for the given reaction is -705.55kJ
Answer:
2HCl is the product of this reaction 2 is added in order to balance the reaction