All GED Science Resources
Example Questions
Example Question #1 : Chemical Bonds
Which of the following types of chemical bonds is very strong and involves transfer of an electron between atoms?
Ionic bonds
Disulfide bonds
Covalent bonds
Hydrogen bonds
Ionic bonds
There are two primary bond types: ionic bonds and covalent bonds. Ionic bonds involve the transfer of an electron between atoms, while covalent bonds require atoms to share an electron between them. Ionic bonds are the stronger of the two. Ionic bonds usually form between a metal and a non-metal (for example, NaCl), while covalent bonds usually form between two non-metals (for example, HCl).
Hydrogen bonds are a type of intermolecular force and are similar to a very weak covalent bond. Hydrogen bonds are not actual bonds, and do not chemically link atoms together; they are strictly physical interactions. Disulfide bonds are covalent bonds between sulfur atoms that help form protein structure.
Example Question #1 : Elements And Compounds
On the periodic table, carbon is atomic number and has an atomic mass of . How many sub-atomic particles are found in the nucleus of a carbon atom?
The standard sub-atomic particles are protons, neutrons, and electrons. Protons and neutrons are found in the nucleus, while electrons move freely around the nucleus. This question is specifically asking about the number of protons and neutrons in an atom of carbon.
Each proton and each neutron has a mass of approximately . Since the atomic mass of a carbon atom is , we can conclude that there are twelve sub-atomic particles in the nucleus (twelve total protons and neutrons).
The atomic number refers to the number of protons in the nucleus of the atom. Since the atomic number of carbon is six, there are six protons in the nucleus. For this question, however, we need the total of both the protons and neutrons (not just the protons).