Notes

Module 5 Earth’s Structure

1. What are elements? (Any material made up of 1 type of atom)

Any substance that cannot be broken down into a simpler-one by a chemical reaction. Elements consist of atoms with the same number of protons in their nuclei, and occur naturally on Earth.

2. Describe the location and charge of the subatomic particles (protons, neutrons, nucleons, electrons) that make up an atom.

Protons have a relative mass of 1 and a charge of +1 they are found in the nucleus of an atom. Neutrons have a relative mass of 1 and no charge, they are also found in the nucleus. Electrons have a relative mass of 1/1836 and a charge of -1. They are found in specific orbits around the nucleus and are held in these orbits by the positive charge of the protons in the nucleus.

3. Why are atoms electrically neutral?

The opposite charges of protons and electrons balance each other producing a zero net charge.

4. Define the following terms associated with the atom:

a. atomic number – the number of protons each atom of a given element contains and its isotopes, used to determine that element's position in the periodic table

b. mass number – the total number of protons and neutrons in the nucleus.

c. atomic mass – is the total mass of protons, neutrons and electrons in a single atom (when the atom is motionless).

d. atomic mass unit – a unit used to express the masses of atoms and molecules, equal to one-twelfth of the mass of a carbon-12 atom

5. What is an Isotope? (An atom of the same element that contain different numbers of neutrons)

6. How do the three isotopes of Hydrogen (H) (hydrogen-1, hydrogen-2, and hydrogen-3) differ?

A hydrogen isotope with only one proton is called hydrogen-1, where 1 is the mass number. A hydrogen isotope with one proton and one neutron is therefore hydrogen-2, and a hydrogen isotope with one proton and two neutrons is hydrogen-3. The three isotopes of hydrogen differ in the number of...