Answer:
those are all physical changes and most physical changes can be undone like crushing a pice of metal you can flatten it back out you anwser is physical change
Explanation:
Answer:
-100 kJ
Explanation:
We can solve this problem by applying the first law of thermodynamics, which states that:

where:
is the change in internal energy of a system
Q is the heat absorbed/released by the system (it is positive if absorbed by the system, negative if released by the system)
W is the work done by the system (it is positive if done by the system, negative if done on the system)
For the system in this problem we have:
W = +147 kJ is the work done by the system
Q = +47 kJ is the heat absorbed by the system
So , its change in internal energy is:

Answer:
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
Answer:
1 and 2
Explanation:
when we r adding chlorine to water
the water is clean
<h3>Answer:</h3>
Correct Option-A (Ability to burn skin)
<h3>Explanation:</h3>
When skin tissues are exposed to Acids or Bases a chemical burn occurs as both of these substances are corrosive in nature. These burns occur without providing any heat, results from a very fast reaction, are extremely painful and causes damage to structures present under skin.
Option-B is incorrect because Acids taste sour, while, Bases taste bitter.
Option-C is incorrect because pH of Acids is less than 7 while, pH of Bases is greater than 7.