Question

Make a sketch of an oxygen atom. Include the correct number of protons, electrons, and neutrons for the most abundant isotope. Use the following symbols: proton \(=\bullet\), neutron \(=o\), electron \(=\bullet\).

Short answer

An oxygen atom has 8 protons, 8 neutrons, and 8 electrons. Sketch the nucleus with 8 protons \(=\bullet\) and 8 neutrons \(=o\), then draw two electron shells; the inner shell with 2 electrons and the outer shell with 6 electrons, all represented by \(=\bullet\).

Step-by-step solution

Determine Atomic Numbers

Gather information about Oxygen from the periodic table. Oxygen has an atomic number of 8, which means it has 8 protons and, in a neutral atom, 8 electrons. The most abundant isotope of Oxygen is Oxygen-16, having 8 neutrons as well.

Sketch the Nucleus

Draw the nucleus of the oxygen atom, which contains both protons and neutrons. Use the symbol \(=\bullet\) for protons and \(=o\) for neutrons. Sketch 8 protons and 8 neutrons inside the nucleus arranged closely.

Add Electrons

Draw two electron shells around the nucleus. The first shell can hold up to 2 electrons and the second can hold up to 8 electrons. Place 2 electrons (using the symbol \(=\bullet\)) in the first shell and the remaining 6 electrons in the second shell, evenly spacing them around the nucleus.

Review and Label Atom Parts

Check the sketch for accuracy making sure the correct numbers of protons, neutrons, and electrons are included and properly symbolized. Label the protons, neutrons, and electron shells if needed to help identify the parts of the atom in the sketch.

Key concepts

Atomic Number

The atomic number is a fundamental characteristic of any element, serving as its unique identifier on the periodic table. For example, oxygen's atomic number is 8, which is pivotal in understanding its position in the periodic table and its chemical properties. This number represents the amount of protons in the nucleus of an atom. Protons are positively charged particles, and the number of protons defines the type of element.

In a neutral atom, the atomic number also indicates the number of electrons present in the orbitals surrounding the nucleus. Electrons are negatively charged particles that counterbalance the positive charge of the protons. Knowing the atomic number thus provides information about both the electrical charge of the nucleus and the electron configuration of an element.

Isotopes

Isotopes are different forms of the same element, which have the same number of protons but a varying number of neutrons. The most common isotope of oxygen is Oxygen-16, which indicates that in addition to the 8 protons, there are also 8 neutrons in the nucleus. Other isotopes of oxygen include Oxygen-17 and Oxygen-18, each having one and two extra neutrons, respectively.

• Oxygen-16 has 8 neutrons.
• Oxygen-17 has 9 neutrons.
• Oxygen-18 has 10 neutrons.

The difference in the number of neutrons among isotopes doesn't affect the chemical behavior of the element significantly, but it does influence the atomic mass and stability of the isotopes. Isotopes may be stable or radioactive, with radioactive isotopes tending to decay into other elements over time.

Electron Shells

Electron shells, also known as energy levels, are the pathways in which electrons orbit around an atom's nucleus. These shells are structured in layers, with each shell farther from the nucleus having a higher energy level. The first shell is the closest to the nucleus and has the lowest energy level. According to the shell model, the first shell can hold up to 2 electrons, and the second shell can hold up to 8 electrons.

For an oxygen atom, drawing two electron shells is necessary. In the first shell, place 2 electrons, representing the most stable configuration for that shell. The second shell will host the remaining 6 electrons, filling up the shell progressively. Electron shells are important because they determine how atoms interact with each other, forming chemical bonds. The arrangement of electrons in the shells significantly influences an element's reactivity and its ability to form molecules.