Write equations for the reactions of
$(i)$ iron with steam
$(ii)$ calcium and potassium with water
$(i)$ $\underset{Iron}{\mathop{3F{{e}_{(s)}}}}\,\,+\,\underset{Steam}{\mathop{4{{H}_{2}}{{O}_{(g)}}}}\,\,\to \,\underset{Iron\,(II,III)\,oxide}{\mathop{F{{e}_{3}}{{O}_{4(aq)}}}}\,\,+\underset{Hydrogen}{\mathop{\,4{{H}_{2(g)}}}}\,$
$(ii)$ $C{{a}_{(s)}}+2{{H}_{2}}{{O}_{(l)}}\to Ca{{(OH)}_{2(aq)}}$ $+{{H}_{2(g)}}+\text{ Heat }$
$(iii)$$\underset{\begin{smallmatrix}
\text{Calcium}\,\text{/} \\
\text{Potassium}
\end{smallmatrix}}{\mathop{2{{K}_{(s)}}}}\,+\underset{water}{\mathop{2{{H}_{2}}{{O}_{(l)}}}}\,\to \underset{\begin{smallmatrix}
\text{Calcium Hydroxide /} \\
\text{Potassium hydroxide}
\end{smallmatrix}}{\mathop{2KO{{H}_{(aq)}}}}\,+\underset{Hydrogen}{\mathop{{{H}_{2(g)}}}}\,+\text{ Heat }$
You are given a hammer, a battery, a bulb, wires and a switch.
$(a)$ How could you use them to distinguish between samples of metals and non-metals ?
$(b)$ Assess the usefulness of these tests in distinguishing between metals and non-metals.
State two ways to prevent the rusting of iron.
Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.
$(a)$ What will be the action of gas on
$(i)$ dry litmus paper ?
$(ii)$ moist litmus paper ?
$(b)$ Write a balanced chemical equation for the reaction taking place.
Name two metals which are found in nature in the free state.
What type of oxides are formed when non-metals combine with oxygen?