Question

Which of the following statements are true? I. Models are always wrong unless they are proved by a theory. II. Elements, such as lead, are made of tiny particles that mostly consist of open space. III. The air you breathe is an example of a heterogeneous mixture. IV. Because NH3 always contains the same relative numbers of atoms, it will always contain 4.6 g of nitrogen for every 1.0 g of hydrogen.

Answer 1

Answer:

The only option that has a true statement is hence only (ii) and (iv) are TRUE

Explanation:

The correct option is (ii) - Elements, such as lead, are made of tiny particles that mostly consist of open space.

for the first option (i) - Models are always wrong unless they are proved by a theory- This is not true because not all models are always wrong and they are not necessarily need to be proved by a theory to ascertain the veracity of the model, one such example is the Neil's bohr model of atom.

for the third option (iii) - The air you breathe is an example of a heterogeneous mixture. This is wrong because Air is a homogeneous mixture containing Nitrogen and Oxygen and other constituents as its composition.

for the last option (iv) - Because NH3 always contains the same relative numbers of atoms, it will always contain 4.6 g of nitrogen for every 1.0 g of hydrogen - this is also  true as the amount contained is dependent on the number of atoms in the balanced equation for the production of ammonia.