Answer:
C
Explanation:
In thermodynamics, a exothermic system looses heat to the surroundings while an endothermic system absorbs heat from the surroundings.
A system is a part the universe marked off by a specified boundary. The contents of the cup constitutes the system in this case.
The region of space outside the system is called the surroundings. Hence everything outside the cup constitutes the surroundings.
Answer:

Explanation:
S is in 3d period, so it has 3 levels
1 level has 2 electrons, 2d level 8 electrons, 3d level 6 electrons

Answer:
Visible light waves
Explanation:
Visible light waves are the only electromagnetic waves we can see. We see these waves as the colors of the rainbow. Each color has a different wavelength. Red has the longest wavelength and violet has the shortest wavelength.
conductor are defined as the materials or substances that allow electricity to flow through them. Also, conductors allow heat to be transmitted through them. Examples of conductors are metals, the human body, Earth and animals. The human body is a strong conductor.
Any material that keeps energy such as electricity, heat, or cold from easily transferring through is an insulator. Wood, plastic, rubber, and glass are good <em><u>insulator</u></em><em><u>.</u></em>
Explanation:
have a beautiful day
Answer:
Addition of a catalyst can speed up a reaction by providing an alternate reaction pathway that has a lower activation energy
Explanation:
A catalyst is an agent that increases the rate of a chemical reaction by providing an alternate pathway for the reaction that requires a lower activation energy. As the requirement for activation energy is less in the presence of a catalyst, there are more reactant particles becoming involved in the chemical reaction and as such there are more products formed per unit time, or there is an increase in the rate of the reaction
Example of catalyst include
1. Addition of potassium permanganate to hydrogen peroxide to aid in the rapid decomposition into water and oxygen
2. Platinum serves as a catalyst in the complete combustion of carbon monoxide into carbon dioxide.