Answer: The correct answer is option B.
Explanation: Reactivity of elements is defined as the tendency to loose or gain electrons.
These reactions are a type of single displacement reactions. A single displacement reaction is a type of reaction in which an element displaces another element in a chemical reaction. These are studied with the help of reactivity series.
The element which lies above in the reactivity series can easily displace the element which lies below in the reactivity series.
Option A: This reaction will not yield a stable product because Zinc lies below Aluminium in the reactivity series.

Option B: This reaction will yield a stable product because Sodium lies above Calcium in the reactivity series.

Option C: This reaction will not yield a stable product because Hydrogen lies below Magnesium in the reactivity series.

Option D: This reaction will not yield a stable product because Calcium lies below Barium in the reactivity series.

Option E: This reaction will not yield a stable product because barium lies below Lithium in the reactivity series.

Answer:
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
Explanation:
This means that a system always has the same amount of energy, unless it's added from the outside.
Explanation:
Since pressure remained constant, we can eliminate P from the equation

Doing some algebra and converting temperature to Kevin by adding 273, you should obtain the same result.
It's a thermodynamic quantity equal to the enthalpy minus the product of entropy and the absolute temperature
Answer:
Sulfur
Explanation:
Sulfur is a chemical element that is represented with the chemical symbol "S" and the atomic number 16 on the periodic table.