D. quantitative data can be recorded.
Answer:
b
Explanation:
The reaction that is not a displacement reaction from all the options is 
In a displacement reaction, a part of one of the reactants is replaced by another reactant. In single displacement reactions, one of the reactants completely displaces and replaces part of another reactant. In double displacement reaction, cations and anions in the reactants switch partners to form products.
<em>Options a, c, d, and e involves the displacement of a part of one of the reactants by another reactant while option b does not.</em>
Correct option = b.
D. 8
You can predict it from it's name "Octet" means Eight. Atom must have that number of electron to have a stable structure!
Hope this helps!
Answer is: elements are always combined in the same proportion by mass.
Law of multiple proportions or Dalton's Law said that the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers.
For example, nitrogen(I) oxide N₂O; m(N) : m(O) = 2·14 : 16 = 7 : 4.
Another example, water (H₂O) is made of two hydrogen atoms and one oxygen atom:
m(H) : m(O) = 2·1 : 16 = 1: 8.