An atom is composed of three major subatomic particles: protons, neutrons, and electrons.

Protons have a positive charge. Neutrons do not carry a charge. Electrons have a negative charge.

The mass of a proton and neutron are approximately the same. Electrons have a significantly smaller mass compared to protons and neutrons (the mass of an electron is 1/1840 of a proton’s mass).

The nucleus of an atom is composed of protons and neutrons being bound together. Electrons orbit around the space surrounding the nucleus.

The number of protons and electrons in an atom are equal. Their opposite charges make the atom electrically neutral.

Isotopes of an element differ in the number of neutrons. This only affects the atomic mass while the chemical properties stay the same. The protons and electrons will still be equal in number.

Recall that a compound is formed when two or more elements are combined in a definite ratio. An example would be a water molecule which is formed from the bonding of two hydrogen atoms and an oxygen atom.

From this example, we can see that the physical and chemical properties of the compound formed is quite different from the elements forming it. While hydrogen and oxygen are flammable gases, water is a liquid which is not flammable.

Ionic bonds involve atoms gaining and losing electrons as they are transferred to another atom.

Covalent bonds involve atoms sharing electrons.

Ionic bonds form a stronger bond than covalent bonds. This is a result of oppositely charged atoms becoming attracted to each other when a neutral atom becomes positively charged (after losing electrons) or negatively charged (after gaining electrons).

In covalent bonds, atoms share electrons with each other to form a bond. Large, complex molecules can be formed as a result of atoms bonding covalently.

The atomic number of carbon is 6. This means that there are 6 protons in a carbon atom. For our example, the carbon atom is neutral. Thus, the number of electrons will be equal to the number of protons. There will be 6 electrons in the carbon atom. The carbon atom will also have 6 neutrons which do not have a charge. Since the atom is not an isotope, the neutrons will have the same number as the protons.

Using the marbles we can let protons be red, the neutrons be yellow, and the electrons be blue (You can designate the marbles in other ways as you prefer such as yellow for electrons and blue for neutrons). The nucleus of an atom is composed of the binding of protons and neutrons. We will then put the red and yellow marbles together. The electrons orbit around the nucleus in the surrounding space. We can then place the blue marbles around the nucleus of the carbon atom.

In the previous question (Question 5), we created a model of a carbon atom using red, blue, and yellow marbles. The nucleus of the model was formed from the forces binding the protons and neutrons. The electrons were placed around the nucleus in the surrounding space where they orbit the nucleus.

The model we created could help us understand the structure of an atom composed of subatomic particles (the protons, neutrons, and electrons). The model can show us how the subatomic particles are arranged for different types of atoms. From our carbon example, we used the information from the atomic number to determine the number of protons and electrons in a neutral carbon atom. Since the atom was not an isotope, the number of neutrons was equal to the number of protons and electrons.

While the model is helpful in this regard, it has limitations in terms of how the subatomic particles are portrayed. The carbon atom model we created is simplified compared to how complex it really is. An example is how significantly smaller in mass electrons are compared to protons. We also won’t be able to accurately portray the orbit of the electrons around the space surrounding the nucleus. So while we are able to apply the general principles regarding the structure of an atom, we cannot capture its complexities in greater detail.

When writing out the formula for an ionic compound, we first write the positively charged ion and then the negative charged ion. Thus, the calcium ion is written first and the chloride ion is written last.

To write the ionic compound, place the numerical value of the charge for one ion as the subscript of the other. Thus, calcium’s subscript will be 1 and chlorine’s subscript will be 2.