Answer:
How can I tell if a chemical reaction is occurring? A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change.
Explanation:
It allows electrons to flow from the anode to the cathode.
Answer:
C: It depends on the entropy and enthalpy of the reaction.
Explanation:
Gibbs free energy is defined as the maximum amount of non-expansion work that can be gotten from a closed system. Now this work is usually done in place of the system’s internal energy and Energy that is not extracted as work is usually exchanged with the immediate surroundings in the form of heat.
Answer:
A
Explanation:
To label an element correctly using a combination of the symbol, mass number and atomic number furnishes some important information about the element.
We can obtain these information from the element provided that correct labeling of the element is presented. Firstly, after writing the symbol of the element, the atomic number is placed as a subscript on the left while the mass number of the atomic mass is placed as a superscript on the same left.
Looking at the question asked, we have the element symbol in the correct position as Ca, with 42 also in the correct position which is the mass number. The third number which is 20 is thus the atomic number of the element.