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:
In a chemical reaction, <u>products</u> are the substances present after the reaction
It's an exciting and interesting process but those 5 points aren't worth a decent answer. The whole process is called fractioned distillation where different temperatures are reached, transforming the crude oil in gas. After being hit by a cold source it colds becoming different hydrocarbons depending on the temperatures.
Answer:
d= 50.23 g/cm³
Explanation:
Given data:
radius = 137.9 pm
mass is = 5.5 × 10−22 g
density = ?
Solution:
volume of sphere= 4/3π r³
First of all we calculate the volume:
v= 4/3π r3
v= 1.33× 3.14× (137.9)³
v= 1.33 × 3.14 × 2622362.939 pm³
v= 1.095 × 10∧7 pm³
v= 1.095 × 10∧-23 cm³
Formula:
Density:
d=m/v
d= 5.5 × 10−22 g/ 1.095 × 10∧-23 cm³
d= 5.023 × 10∧+1 g/cm³
d= 50.23 g/cm³
B. 8
Although it may seem that transition metals would have more than 8 valence electrons, they in fact do not.