Deduce the numbers of protons, neutrons and electrons in the bromide ion shown, $^{81}_{35}\text{Br}^-$.
Complete Fig. 4.1 by adding these formulae to the diagram: • 2HBr • H$_2$ + Br$_2$.
Explain how Fig. 4.1 shows that the reaction is endothermic.
Complete this sentence about an endothermic reaction using a word from the list. products, reactants, bromine, surroundings An endothermic reaction transfers thermal energy from the [BLANK].
Write the formula of the ion present in every acid.
Complete the word equation for the reaction between any acid and any carbonate. acid + carbonate → [BLANK] + [BLANK] + [BLANK]
A few drops of litmus indicator are added to a dilute acid. State the colour of the solution.
Label Fig. 4.2 to show the cathode and the electrolyte.
Name the products and state the observations at the positive and negative electrodes.
State one property of graphite that makes it useful as an electrode.