Answer: Gamma-rays have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and in nuclear explosions. Gamma-rays can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells.
Explanation: :)
Answer:
15 kJ
Explanation:
We need to know the following;
what is activation energy?
- Activation energy is the minimum energy required by reactants for a chemical reaction to take place.
What are catalysts?
- Catalysts are molecules or substances that speed up the rate of a chemical reaction.
- In other words, catalysts increase the speed at which products are formed from reactants.
How do catalysts speed up reactions?
- Catalysts speed the rate of chemical reactions by lowering the activation energy of the reactants.
- When activation energy is lowered, reactants require less energy for the reaction to occur which easily achieved making the reaction proceed faster.
- Therefore, in presence of a catalyst, the new activation energy should be lower than the initial value of activation energy.
Explanation:
One of the moments most valued by astronomers is twilight. As the Sun sets, the sky darkens and the first stars are seen. At first there are two or three, but as the minutes go by they become more and more visible; the first to appear will be the brightest stars of the night, the last, the dimmest. But their brightness is not the only thing that differentiates the stars. As the night progresses and the sky darkens, if we look closely, we will see stars of red, white and blue… Stars have colours, and learning about them takes us on a fascinating journey through their lives.
During these early spring weeks, it is easy to locate the constellation of Orion, along with Canis Major and Taurus, shortly after sunset. At first sight, the stars might appear to have the same colour, but if we seek out a dark sky and take a second closer look, we will notice different colours. Sirius (in Canis Major) is white, Rigel (Orion’s right foot) is blue, Aldebaran (in Taurus) is orange and Betelgeuse (Orion’s left shoulder) is red.
