__________ rocks forms when a rock is changed by heart,pressure, or chemical reactions.

a) Igneous
b) Sedimentary
c) Metamorphic
d) Chemical

what exactly is metamorphic?

The correct answer is c) Metamorphic.

To understand why, let's break down the options and their characteristics:

a) Igneous rocks are formed through the cooling and solidification of molten material called magma or lava. This process occurs either beneath the Earth's surface (intrusive igneous rocks) or on the surface (extrusive igneous rocks). Igneous rocks are not formed through heat, pressure, or chemical reactions, but rather from the cooling of molten material.

b) Sedimentary rocks are formed from the accumulation and cementation of sediments (e.g., sand, mud, and pebbles) over time. These sediments are derived from various sources like the erosion of pre-existing rocks, mineral precipitation from water, or the remains of organisms. Sedimentary rocks are not formed through heat, pressure, or chemical reactions, but through sedimentation and lithification.

c) Metamorphic rocks, on the other hand, are formed when any type of pre-existing rock undergoes significant changes due to heat, pressure, or chemical reactions. These changes occur deep within the Earth's crust as a result of the immense heat and pressure exerted on the rocks over time. This process, called metamorphism, causes the mineral composition and texture of the original rock to change, resulting in the formation of a new rock type.

d) The option "Chemical" is not accurate because it does not specify what type of rock is being referred to. Rocks are not formed solely from chemical reactions; rather, chemical reactions can contribute to the transformation of rocks, as seen in the formation of metamorphic rocks.

Therefore, the correct answer is c) Metamorphic, as it accurately describes the formation process involving the alteration of existing rocks through heat, pressure, or chemical reactions.