Working with chemical equations

Solution Preview

1. Describe the structure of an atom and the subatomic particles from which it is made?

An atom is the smallest particle that retains the chemical properties of an element. The structure of an atom is made up of a central nucleus and negatively charged particles called electrons that surround the nucleus at different energy levels. As well, there are also particles contained on the nucleus, which include positively charged protons, and neutral neutrons. All atoms of the same element have the same atomic number (Z). The atomic number is equal to the number of protons in the atom's nucleus or the number of electrons surrounding the atom's nucleus. The mass number (A) of the atom is equal to the number of protons plus the number of neutrons. The subatomic particles are the electrons, protons, and neutrons.

2. Describe the following terms and give examples for each one:

• Element is a fundamental substance that can't be chemical changed or broken down into anything simpler. An example would be oxygen, O2, or sodium, Na.

• Isotopes are atoms with identical atomic numbers but different mass numbers. An example is Neon, Ne (Atomic number of 10), and sodium ion, Na+ (Atomic number of 11) with one less electron, making the atomic number 10.

• Atomic number is represented by Z and it is the number that the elements are arranged in the periodic table. It is equal to the number of protons in the atom's nucleus, or the number of electrons surrounding the atom's nucleus. An example is sodium, ...