Slow chemical change
It is a chemical change because the erosion is due to the chemical reaction between the acid and the in the rain and the calcium carbonate.
It is slow due to the concentration of acid is low.
Explanation:
magnesium Hydroxide + Hydrochloric react together and give us magnesium chloride + water
iii. True. The existence of a vacancy in a crystal decreases the energy of the material.
One of the scientific disciplines called crystallography examines how the atoms in a solid crystal are arranged. When molecules are linked together in a regular way, these crystals are created.
The mechanical, physical, and optical properties of a material can alter when crystal flaws are present. The strength of the material can be impacted by a flaw.
An irregularity in the atoms' regular geometrical arrangement within a crystalline material is referred to as a crystal defect. These flaws are caused by the solid being deformed, cooling quickly from a high temperature, or being exposed to high-energy radiation (such as X-rays or neutrons). because the vacancy cause defects and the crystal structure is disturbed this causes a decrease in energy.
To know more about vacancy visit the link:
brainly.com/question/14937309?referrer=searchResults
#SPJ4
the formula of the heavy water is D2O
