1. The metamorphic rocks are produced when the parent or the pre-existing rocks (whether sedimentary, igneous, or even metamorphic) are changed by pressure, heat, and the chemical activity of the fluids.
When the prime changing factor is heat, generally due to direct contact, it may go through fundamental modification in recrystallization and texture is known as contact metamorphism. While regional metamorphism takes place when the minerals and texture of the rock are modified by pressure and heat.
Oxidation: a chemical change resulting form a reaction with oxygen
Endothermic:a reaction that takes in energy
Exothermic: a reaction that releases energy
Decomposition:chemical change whereby a molecule breaks down into simpler moles clues or elements
Subscript:written underneath or below
Answer:
The shape of a molecule is mostly determined by repulsion among the pairs of electrons around a central atom.
When an atomic nucleus emits an alpha particle it decay into an atom with atomic number 2 less and mass number 4 less. Thus Thorium 230 decay as follows.
230 90Th -------> 226 88Th + 4 2 He
thorium is in the atomic number 90 thus it during alpha decay it reduces to atomic number 88 while its 230 mass number reduces to 226
