Question

Distinguish between atoms and molecules and among protons, neutrons, and electrons.

Short answer

Atoms are the smallest units of an element, consisting of a nucleus (containing protons and neutrons) and electrons orbiting the nucleus. Molecules are formed when two or more atoms bond together, creating a specific chemical compound. Protons are positively charged particles in the nucleus, determining the element's identity. Neutrons, also located in the nucleus, are neutral particles influencing an atom's isotope. Electrons are negatively charged particles orbiting the nucleus, participating in chemical reactions and bonding. Protons and neutrons have similar size and mass, while electrons are considerably smaller and lighter.

Step-by-step solution

Defining Atoms and Molecules

Atoms are the smallest units of an element that still retain the properties of that element. They are composed of a nucleus, which consists of protons and neutrons, and electrons that orbit around the nucleus. Molecules, on the other hand, are formed when two or more atoms are bonded together. These atoms can be of the same element or different elements, and the type and number of atoms in a molecule define its specific chemical compound.

Distinguishing Between Protons, Neutrons, and Electrons

Protons, neutrons, and electrons are called subatomic particles, as they are the fundamental building blocks of atoms. Here's a brief overview of their differences: 1. Protons: These are positively charged particles found in the nucleus of an atom. The number of protons in an atom defines its atomic number and determines what element it is. 2. Neutrons: Neutrons are neutral particles found in the nucleus of an atom. They have no electric charge. The number of neutrons in an atom helps define its isotope. 3. Electrons: Electrons are negatively charged particles that orbit the nucleus of an atom. They are involved in chemical bonding and reactions. The number of electrons in an atom is equal to the number of protons, making the atom electrically neutral overall.

Comparing Sizes and Masses

One significant difference among protons, neutrons, and electrons is their size and mass: - Protons and neutrons are roughly the same size and mass, with both having a mass of approximately \(1 \times 10^{-27}\) kg. They make up most of the mass of an atom. - Electrons are much smaller and lighter, with a mass of around \(9.11 \times 10^{-31}\) kg. Due to their negligible mass, they do not contribute significantly to the overall mass of an atom.

Understanding their Role in Chemical Reactions

Chemical reactions involve the rearrangement of electrons in the outermost shells of atoms known as the valence electrons. While protons and neutrons are not directly involved in chemical reactions, their presence in the nucleus helps define the chemical properties of the elements and their atoms. In conclusion, atoms and molecules are different structures where atoms represent single units of an element, and molecules consist of two or more bonded atoms. The fundamental building blocks of atoms are protons, neutrons, and electrons, which differ based on their charge, mass, and role in chemical reactions.