Answer:
Explanation:
13 ) symbol of enthalpy change = Δ H .
14 ) enthalpy change is nothing but heat absorbed or evolved .
During fusion enthalpy change
Δ H .= m Lf , m is mass and Ls is latent heat of fusion
During evaporation, enthalpy change
Δ H .= m Lv , m is mass and Lv is latent heat of evaporation
during temperature rise , enthalpy change
Δ H = m c Δ T
In case of gas , enthalpy change can be calculated by the following relation
Δ H = Δ E + W , Δ E is change in internal energy , W is work done by gas.
15 ) When enthalpy change is negative , that means heat is released to the environment .So reaction is called exothermic .
when heat is absorbed enthalpy change is positive . Reaction is endothermic.
Yes, that's correct. It's the tepid latitude.
All the elements in one group have the same number of valence electrons.
Answer:
A) Age!! Its because even if the object was 1 year old or 100 years old, nothing about the impact would change. However, those other categories depict features that would definitely make an impact. For example as object that is big, fast, and hits at an angle perpendicular to whatever it is moving towards, the impact will be very lage. But if its the opposite and it was small and slow, then the impact crater would not be as large. Good luck on your quiz!!
<h3><u>Answer;</u></h3>
It makes the reaction harder to start
<h3><u>Explanation</u>;</h3>
- <em><u>Activation energy is minimum amount of energy that is required for a reaction to start. Activation energy determines the rate of a chemical reaction such that the higher the activation energy, the lower the rate of chemical reaction and vice versa.</u></em>
- The source of activation energy needed to push chemical reactions forward is obtained from the surroundings. Catalyst speed up chemical reaction by lowering the activation energy. Therefore, catalysis is the increase in the rate of a chemical reaction by lowering its activation energy.
