The Periodic Table consists of elements arranged in order of increasing atomic number.
(i) What is meant by the term atomic number?
A the number of protons in the nucleus of an atom B the 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
(ii) Elements in the same period of the Periodic Table:
A react in similar ways B have the same number of occupied electron shells C have the same number of electrons in their outer shell D have the same relative atomic mass
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 oxidebasicacidicacidic \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} & & \text{acidic} \\ \hline \end{array} melting pointstructureacid-base character of the oxideNagiantbasicMgSihighPlowmolecularacidicSlowmolecularClacidicComplete the table by writing one of these words in each blank space:
