True some explanations are not always based on empirical evidence
Answer:

Explanation:

The incomplete combustion of alkanes, and other fuels actually, happens when there is a limited supply of oxygen. Instead of the fuel burning completely to produce carbon dioxide, it produces carbon monoxide instead.
This gas is harmful to jumans because it combines with haemoglobin in lood and takes up space that belongs to oxygen which can lead to suffocation or even death
I believe the answer is a because 2 times 12 is 24. Hope this helped
Answer:(4) ----accepts a proton
Explanation:
H2O water can produce both hydrogen and hydroxide ions
H2O --> H+ + OH-
According to the Bronsted-Lowry theory, it can be a proton donor and a proton acceptor.this means that It can donate a hydrogen ion to become its conjugate base, or can accept a hydrogen ion to form its conjugate acid,
When , a water molecule, H2O accepts a proton it will act as a Brønsted-Lowry base especially when dissolved in a strong acidic medium. for eg
HCl + H2O(l) → H3O+(aq) + Cl−(aq)
Here, Hydrochloric acid is a strong acid and ionizes completely in water, since it is more acidic than water, the water will act as a base.