The Periodic Table consists of elements arranged in order of increasing atomic number.
What is meant by the term atomic number?
A the total number of protons in the nucleus of an atom B the total number of neutrons in the nucleus of an atom C the total number of protons plus neutrons in an atom D the total number of protons plus electrons in an atom
Elements in the same group of the Periodic Table exhibit similar chemical properties. This similarity arises because their atoms all possess the same number of:
A protons in the nucleus B neutrons in the nucleus C electrons in the outer shell D occupied electron shells
The elements in the periods of the Periodic Table show a change in properties across the period from left to right. The table gives information about some elements in Period 3: sodium (Na\text{Na}Na), magnesium (Mg\text{Mg}Mg), silicon (Si\text{Si}Si), phosphorus (P\text{P}P), sulfur (S\text{S}S), and chlorine (Cl\text{Cl}Cl).
NaMgSiPSClmelting pointhighlowlowstructuregiantmolecularmolecularacid-base character of the oxidebasicacidic \begin{array}{|l|c|c|c|c|c|c|} \hline & \mathbf{Na} & \mathbf{Mg} & \mathbf{Si} & \mathbf{P} & \mathbf{S} & \mathbf{Cl} \\ \hline \text{melting point} & & & \text{high} & \text{low} & \text{low} & \\ \hline \text{structure} & \text{giant} & & & \text{molecular} & & \text{molecular} \\ \hline \text{acid-base character of the oxide} & \text{basic} & & & \text{acidic} & & \\ \hline \end{array} melting pointstructureacid-base character of the oxideNagiantbasicMgSihighPlowmolecularacidicSlowClmolecularComplete the table by writing one of these words in each blank space:
