Answer:
a: chemical change because the change cannot be reversed.
b: physical change because the action can be reversed.
c: chemical change.
d:chemical change.
any change that cannot be reversed is a chemical change and any change that can be reversed is a physical change.
Answer:
Igneous rock is the type of rock that forms as a result of cooling an crystallization
Explanation:
- Rocks are either sedimentary, igneous or metamorphic based on the chemical composition and the mode of formation.
- Igneous rocks are formed as a result of the cooling and crystallization of magma from volcanic eruptions.
- Igneous rocks are either intrusive, which form deep in the crust or extrusive which form on the surface of the earth.
- Sedimentary rocks are formed as a result of deposition, and cementation of sediments.
- Metamorphic rocks, on the other hand, are formed from the sedimentary and igneous rocks during the rock cycle.
Answer:
Nitrogen, 
Explanation:
Hello,
This is a clear example of what the ideal gas equation is used for, thus, from its mathematical definition:

One can spell it out in terms of mass and molar mass:

Now, solving for the molecular mass,
:

Now, by taking into account that the gas is diatomic, the matching gas turns out to be nitrogen.
Best regards.