Question

Correct each of the following misstatements from Dalton's atomic theory. a. Elements are made of tiny particles called molecules. b. All atoms of a given element are very similar. c. The atoms of a given element may be the same as those of another element. d. A given compound may vary in the relative number and types of atoms depending on the source of the compound. e. A chemical reaction may involve the gain or loss of atoms as it takes place.

Short answer

a. Correction: Elements are made of tiny particles called atoms. b. Correction: All atoms of a given element are identical in mass and properties. c. Correction: Atoms of one element are different from those of another element in terms of atomic mass and properties. d. Correction: A given compound always contains the same relative number and types of atoms, regardless of its source. e. Correction: A chemical reaction involves the rearrangement of atoms during the process, but no atoms are created or destroyed.

Step-by-step solution

a. Elements are made of tiny particles called molecules.

Correction: Elements are made of tiny particles called atoms.

b. All atoms of a given element are very similar.

Correction: All atoms of a given element are identical in mass and properties.

c. The atoms of a given element may be the same as those of another element.

Correction: Atoms of one element are different from those of another element in terms of atomic mass and properties.

d. A given compound may vary in the relative number and types of atoms depending on the source of the compound.

Correction: A given compound always contains the same relative number and types of atoms, regardless of its source.

e. A chemical reaction may involve the gain or loss of atoms as it takes place.

Correction: A chemical reaction involves the rearrangement of atoms during the process, but no atoms are created or destroyed.

Key concepts

Atomic Structure

Understanding the atomic structure is crucial in grasping the basics of chemistry. Atoms are the smallest units of matter that retain the identity of an element. Imagine them as tiny building blocks, each with its own unique set of characteristics. Inside the atom, there's a nucleus, made up of protons and neutrons, with electrons orbiting around it much like the way planets circle the sun.

Remember Dalton's corrected statement: Elements are made of tiny particles called atoms. These atoms are unique to each element, differing in atomic mass and properties – a fact that fundamentally refutes the misstatement that atoms of different elements might be the same. Picture each element on the periodic table as having its own 'fingerprint' of sorts, composed of atoms with a distinct number of protons in their nuclei.

For instance, every atom of hydrogen has one proton, making it distinctly hydrogen, whereas every carbon atom has six protons, a characteristic signature for carbon. This uniqueness lays the foundation for chemical bonding and reactions as atoms combine in distinct ways to form molecules and compounds.

Chemical Reactions

Moving on to chemical reactions, these are processes where substances (reactants) undergo a transformation to form new substances (products). It’s like a dance where the atoms in the reactants pair up differently to create new structures. This is best understood when considering Dalton's correction: A chemical reaction involves the rearrangement of atoms, but no atoms are created or destroyed.

To further elucidate, let's take the simple reaction of hydrogen gas reacting with oxygen gas to form water: \[2 \text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}\]. Here, atoms of hydrogen and oxygen are rearranged to form water molecules, but none of the atoms are lost or gained in the process. This rearrangement is the core of all chemical change and underscores the principle that while the substances may change form or combine with others to create something new, the atomic 'ingredients' remain constant throughout.

Conservation of Mass

Finally, let's explore the conservation of mass, an essential concept in both physics and chemistry that indicates mass is neither created nor destroyed in a closed system. When Dalton corrected the misstatement about compounds varying depending on the source, he was underlining this very principle. Regardless of where a compound comes from, it will consist of the same types and numbers of atoms.

To make this more relatable, think of baking a cake. You start with specific amounts of ingredients (flour, eggs, sugar, etc.), and after baking, you still have the same total mass of ingredients just in a different form - the cake. This analogy holds true for chemical reactions: the total mass of the reactants equals the total mass of the products.

In essence, during chemical reactions, like the formation of water from hydrogen and oxygen, the mass of the resulting water will be precisely the sum of the mass of the hydrogen and oxygen gases that reacted. This concept is fundamental in stoichiometry, the method used to calculate relative quantities of reactants and products in chemical reactions.