Answer: 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The balanced reaction between aqueous calcium chloride reacts with aqueous potassium carbonate is shown as:

Answer:
Because in elastic collisions there is no heat emission or absorption.
Explanation:
A collision is considered elastic when the total kinetic energy of the study system is conserved during the collision. Since the total kinetic energy is conserved, heat is not emitted or absorbed during the collision. Since the emission or absorption of heat is what produces changes in temperature, If the system remains at a constant temperature, there were only elastic collisions.
There are six atoms in the carbon
Limestone is mainly made up of calcium carbonate, CaCO3. When it is heated, it breaks down to form calcium oxide and carbon dioxide. Calcium oxide reacts with water to produce calcium hydroxide. But if u wanna know how it is formed? It's formed by erosion and weathering which is a type of 'Sedimentary Rock'. Erosion and weathering, carried rocks and end up at the sea or ocean. Which is the end way to go! At there, rocks combined by adding more and more just under the sea. The combination of rocks made it harden. First, it was just small little eroded particles end up at the sea. But at last, it became a very hard rock which isn't easy to break!
Answer:
The answer is B. Limiting factors can lower birth rates, increase death rates.