Weak acids such as carbonic or sulfuric acid react with rocks in the ground, such as limestone. Groundwater reacts with limestone and the dissolving of limestone takes place which forms karst features, such as caverns.
The superscript of element Cl⁻ indicates it is a negative ion.
Answer:
Explanation:
It is called a double circulatory system because blood passes through the heart twice per circuit. The right pump sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart. The left pump sends the newly oxygenated blood around the body.
Classifying things by observation can best be done by using a : Taxon
Taxon divided organisms into different groups based on their unique similarities, which is the best way to classify things if you're doing it by observation.