<span>Frequency x Wavelength = Speed of light
Now, speed of light = 3 x 10^5 km/s = 3 x 10^8 m/s = 3 x 10^10 cm/s
Frequency = speed/Wavelength
= (3 x 10^10)/(4.257 x 10^-7)
=7 x 10^16 Hz</span>
I see I'm late but I believe it's A. , opposites attract. I'm taking the test right now lol
The circuit is no longer closed.
In exothermic reactions, heat and light are released to the surrounding environment. On the other hand, in an endothermic reaction, heat is required and therefore it can be considered as a reactant.
- In exothermic reactions, light and heat are released into the environment (Option D).
- Exothermic reactions release energy in the form of heat or light.
- Combustion reactions are generally exothermic reactions.
- After an exothermic reaction takes place it is possible to observe that the energy of the products of the reaction is lesser than the energy of the reactants.
- The energy released in exothermic reactions is evidenced by the increase in temperature of the reaction.
Learn more in:
An element with 83 protons has the atomic number 83. If you look at a periodic table you will see Bismuth is the element with the atomic number of 83. It will have a positive charge of +3 because it has only 80 electrons and 83protons. 83-80=+3.