Well you want the answer with the same letter in it. A.k.a 2. This means they have the same element in them
O2 (Diatomic oxygen that we breathe) and O3 (Ozone that would be deadly to breathe) have different structures.
So the answer is 2
Answer:
Fossils, the shape of continents, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks.
Explanation:
Fossils, the continent's shape, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks on the sea floor are the evidences that support the theory of plate tectonics in the area. Fossils provides information to us when and where plants and animals once existed. Due to diverging plates, some life became isolated, and evolved into new species. Continental ‘fit’ through coastline matching. Some division of continents look as though they should fit together, e.g. South America and Africa.
Acid is anything which will give H+ to other species.
Have a look at the equations given.
In A) HCl changes to Cl- by giving its H+ to H2O. So HCl is an acid.
In B) HCO3- changes to H2CO3^2- by accepting H+. It did Not give its H+ rather it takes from other species. So it is not an acid at all.
In C) H2O is just breaking to H+ and OH-. It is not giving H+ to other species. So it is also not an acid in this reaction.
In D) HCOOH is giving its H+ to H2O. So it is also an acid.
So out of all reactions with water. The only two species are acting as acid with water namely HCl and HCOOH.
Out of these two HCl is very strong acid but HCOOH is a weak acid.
So the answer is D
