Question

Apply Six atoms of Element A combine with 15 atoms of Element B to produce six compound particles. How many atoms of Elements A and B does each particle contain? Are all of the atoms used to form compounds?

Short answer

Each compound particle contains 1 atom of Element A and 2.5 atoms of Element B. Since the number of Element B atoms per particle is not a whole number, not all atoms are used to form compounds. The given combination is not a perfect molecular formula representing a whole compound particle, suggesting that some atoms of Element B might be left unused during the combination.

Step-by-step solution

Break down the given information

We have the following given information: - 6 atoms of Element A are combined - 15 atoms of Element B are combined - These combined atoms produced 6 compound particles

Calculate the number of atoms of Element A in each particle

Since 6 atoms of Element A combine to form 6 compound particles, we can determine the number of atoms of Element A in each particle by dividing the number of combined atoms by the number of particles: \( Number \, of \, A \, atoms \, per \, particle = \frac{6 \, A \, atoms}{6 \, particles} = 1 \, A \, atom \, per \, particle \)

Calculate the number of atoms of Element B in each particle

Similarly, to find the number of atoms of Element B in each particle, we need to divide the number of combined atoms by the number of particles: \( Number \, of \, B \, atoms \, per \, particle = \frac{15 \, B \, atoms}{6 \, particles} = 2.5 \, B \, atoms \, per \, particle \)

Determine if all atoms are used in the compounds

Since the number of Element B atoms per particle is not a whole number, this indicates that not all the atoms of Element B are used to form the compound particles. Moreover, the ratio of Element A and Element B atoms is not a whole number, which means that the given combination is not a perfect molecular formula representing a whole compound particle. A possible reason could be that some atoms of Element B were left unused during the combination.

Key concepts

Chemical Combination

Chemical combination refers to the process by which two or more elements react to form new substances called compounds. When elements combine, they do so in a fixed, definite proportion by mass, according to the law of constant composition. Consider a practical example where six atoms of Element A combine with fifteen atoms of Element B. The process implies there is a chemical reaction where A and B are reacting in a specific ratio to form a new substance.

In this given exercise, for each compound particle formed, we intuitively expect that the atoms of A and B will be present in whole numbers since compounds are composed of whole atoms. When examining the result of the combination, we observe that while Element A maintains a simple ratio, one atom of A per compound particle, Element B does not, as it presents with 2.5 atoms per particle. This inconsistent ratio is a cue that the combination did not perfectly follow the law of definite proportions, suggesting an incomplete reaction where some atoms of B might not be involved in the chemical combination. Understanding chemical combinations is vital as it explains how different substances interact at an atomic level to create new materials with distinct properties.

Atomic Ratio

The atomic ratio in a compound indicates the number of atoms of one element compared to the number of atoms of another element in the compound. It is the simplest whole-number ratio of atoms present in a compound. In our example, initially, it may seem as though the atomic ratio of Element A to Element B in a compound particle would be 1:2.5 as calculated from the given data, which suggests six atoms of A combine with fifteen atoms of B to form six particles.

However, the atomic ratio must be represented by whole numbers since you can't have a fraction of an atom in a compound. Therefore, the decimal point in the ratio indicates an issue with the chemical combination, possibly having extra atoms of B that don't contribute to the formation of the compound. Understanding atomic ratios helps clarify which reactants are needed and in what quantities to form desired chemical compounds. In developing chemical equations or anticipating the outcomes of reactions, recognizing and applying the concept of atomic ratio is essential for precision and avoiding any excess of unreacted elements.

Molecular Formula

A molecular formula shows the exact number of atoms of each element present in a single molecule of a compound. These are denoted using the chemical symbols of the elements, followed by subscript numbers indicating the number of atoms of each element. For instance, if we had two atoms of hydrogen and one atom of oxygen combining, we would represent water's molecular formula as H₂O.

In the case of our textbook exercise, initially, it appears challenging to deduce a definite molecular formula because Element B exhibits a fractional number of atoms per compound particle, which is not physically possible. In a correct molecular formula, all constituent elements are represented by whole numbers, reflecting the actual count of atoms within a molecule. If the scenario in our exercise were real, we would need to adjust the quantity of Element B so that it aligns with Element A in a whole number ratio to provide an accurate molecular formulation. Thus, a valid molecular formula might not exist for the combination presented in the exercise, hinting that the reaction was incomplete or that additional information is required to arrive at a balanced chemical equation.