Question

Consider the sodium atom and the sodium ion. (a) Write the chemical symbol of each. (b) Do these particles have the same number of nuclei? (c) Do they have the same number of protons? (d) Could they have different numbers of neutrons? (e) Do they have the same number of electrons?

Short answer

The chemical symbol for a sodium atom is Na, and for a sodium ion is Na+. Both have the same number of nuclei and protons, which is one and 11, respectively. They could have different numbers of neutrons if they are different isotopes, but in general, a specific sodium atom and its ion have the same number of neutrons. Lastly, they do not have the same number of electrons since the ion has lost one electron.

Step-by-step solution

Identify the Symbols

The chemical symbol for the sodium atom is written as Na from its Latin name Natrium. A sodium ion that has lost one electron is denoted as Na+.

Nuclei Comparison

The number of nuclei refers to the number of atoms. Since both the sodium atom and the sodium ion originate from the same single atom, they have the same number of nuclei, which is one.

Proton Count

The number of protons defines the element and is equivalent in the sodium atom and the sodium ion. For sodium, this is 11 protons.

Neutron Numbers

Atoms can have different numbers of neutrons, which are isotopes. Both the sodium atom and sodium ion could have different numbers of neutrons, but this does not change when an atom becomes an ion, so if a specific sodium atom and its ionized form are compared, they would have the same number of neutrons.

Electron Count

The sodium ion has one less electron than the sodium atom because it loses an electron to become positive. Therefore, they do not have the same number of electrons.

Key concepts

Chemical Symbols

Chemical symbols serve as shorthand to denote elements in the periodic table and help streamline discussions in chemistry. The symbol for a sodium atom is 'Na', which hails from the element's Latin name, 'Natrium'. In contrast, a sodium ion, which is a sodium atom that has lost an electron, is represented as 'Na+'. This '+' sign indicates a positive charge, a characteristic feature of cations – positively charged ions.

Understanding the chemical symbols is essential because it allows us to quickly identify the substances involved in chemical reactions and their states. For instance, seeing 'Na+' immediately informs us that we're dealing with a sodium ion rather than a neutral atom, which has implications for the atom's reactivity and interactions with other substances.

Atomic Structure

The atomic structure of an element is like the foundation of a building—it dictates the element's properties and behaviors. At the center of an atom lies the nucleus, which contains protons and neutrons. Protons carry a positive electrical charge, whereas neutrons are neutral. The protons in the nucleus identify the element: for example, all sodium atoms have 11 protons. Surrounding the nucleus are electrons, negatively charged particles that occupy various energy levels in an area known as the electron cloud.

The intricate arrangement of these subatomic particles maintains a balance of charges in neutral atoms. However, when electrons are gained or lost, ions are formed, which leads us to the fascinating process of ionization and the creation of charged entities such as the sodium ion.

Protons and Neutrons

Protons and neutrons are the heavyweight contenders in an atom's nucleus, determining its mass and identity. Every element on the periodic table is defined by its proton count, known as the atomic number. Sodium invariably has 11 protons, regardless of whether it's in its neutral atomic form or as an ion. This constancy is what makes an element unchanging in its essence.

Neutrons, on the other hand, contribute to the mass but not the charge of the atom. Sodium can have different amounts of neutrons, a variation that produces isotopes, which are forms of an element with different atomic masses. However, the number of neutrons in a sodium atom or ion remains unchanged during ionization—the process that converts an atom into an ion.

Electrons and Ionization

Electrons are the dynamic and interactive component of an atom, and their behavior leads to ionization. Ionization occurs when an atom either gains or loses electrons, altering its electric charge. For sodium, losing an electron results in a sodium ion (Na+). This single electron loss may seem minor, but it has a dramatic effect on the atom's electrical charge and its chemical properties.

The sodium atom starts as neutrally charged, with an equal number of protons (positive charges) and electrons (negative charges). Once it loses an electron, the sodium atom becomes a sodium ion with a net positive charge due to having one more proton than electrons. This change in electron count not only transforms the atom into an ion but also modifies how it interacts with other atoms and molecules, making ions key players in chemical reactions.