We subtract the enthalpies of the reactants from that of the products:

Since this is < 0, this is an exothermic reaction.
2.998e^8 is how I would write it. If you want it with the least amount of decimals, use 3e^8
Illegal Explosives. Illegal explosives associated with the fireworks season are inherently dangerous because of their composition and unpredictability. Homemade explosives can pose a particular risk for injury because the people making them often lack knowledge and experience in manufacturing fireworks.
Answer:
built a special cavity where the electromagnetic quantum states resonate with the natural vibrations of the atoms. In doing so, one cancouple a photon-based oscillator to a mechanical oscillator, controlling the mechanical quantum states with visible light. The result is a prototype of a quantum transducer, a device that converts light energy into mechanical energy (sound energy)
Explanation:
Sound energy is created by vibrating particles of medium that propagates as a wave. So in order to convert light (electromagnetic wave) to sound wave it has to be converted into electric or magnetic signals. Then these signals can be converted into sound waves.
However, if you consider the particle nature of light. It contains momentum and after collision sets the other particles into oscillatory motion but the wavelength of these vibrations is too high to be considered as sound waves.
Answer:
E. 16.6 mol HCl
Explanation:
The equation for the reaction is;
Zn + 2 HCl --> ZnCl2 + H2
From the reaction 2 moles of HCl produces 1 mole of ZnCl2
Therefore; 8.3 moles of ZnCl2 will be produced by;
= 8.3 moles ×2
= 16.6 Moles of HCl
Therefore; E. 16.6 mol HCl