Answer:well the ice preserves the wooly mammoths
Explanation:its not just snow its bacteria witch means that once living to frozen thats how they know how it looks like and to see what animal its related to now day it related to the elephants
Explanation:
- Evaporation is defined as a process in which liquid state of water is changing into vapor state.
So, we need to break the bonds of liquid substance in order to convert it into vapor state. And, energy is absorbed for breaking of bonds which means that evaporation is an endothermic process.
Hence, the statement evaporation of water is an exothermic process is false.
- When a hydrocarbon reacts with oxygen and leads to the formation of carbon dioxide and water then this type of reaction is known as combustion reaction.
A combustion reaction will always release heat energy. Hence, combustion reaction is exothermic in nature.
- When energy is transferred as heat from the surroundings to the system then it means energy is being absorbed by the system. And, absorption of heat is an endothermic process for which
is positive.
- Whereas when energy is transferred from system to the surrounding then it means energy is released by the system which is an exothermic process.
Hence, for an exothermic process value of
is negative.
Thus, we can conclude that statements which are true are as follows.
- A combustion reaction is exothermic.
- When energy is transferred as heat from the system to the surroundings,
is negative.
- For an endothermic reaction Deta H is positive.
Answer:
They allow particles to stay close together.
The attractive forces (bonds) in a liquid are strong enough to keep the particles close together, but weak enough to let them move around each other. For example, Liquids are useful in car brake systems because they flow and cannot be compressed.
Explanation:
Hope this helps :)
(J) unit joule is the standard unit of heat (energy)
Answer:
if you mix any halogen with any alkali then ionic salt will be formed and also this will cause an exothermic reaction in which heat is getting released