Final answer:
The reaction between calcium and hydrochloric acid produces calcium chloride and hydrogen gas.
Step-by-step explanation:
When calcium (Ca) is mixed with hydrochloric acid (HCl), the reaction is a single-displacement reaction. Calcium will displace the hydrogen in hydrochloric acid, and the products of this reaction will be calcium chloride (CaCl2) and hydrogen gas (H2). Therefore, the correct answer is 1) CaCl2 + H2.
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation.
Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.