The number of protons of elements P and Q are 15 and 17 respectively. What is the formula of the compound formed when P combines with Q?

Which of the following substances is not an electrolyte?

Diagram 4 shows a voltaic cell. What are the products that are formed at the anode and cathode?

Which of the following equations represents the reaction between magnesium and oxygen gas?

Diagram 6 shows the electronic structure of the ion, M³⁺. What is the number of valence electrons of atom M?

Which substance forms a white precipitate when added to sodium sulphate, Na₂SO₄ solution?

Which of the following is the correct observation when magnesium carbonate is heated?

Which of the following is not used as a chemical fertiliser?

Which statement is correct about a polymer?

Diagram 11 shows the electron arrangement of the magnesium atom. Which of the following is correct about this atom?

Which substance exists as molecules?

Which of the following is the use of the carbon-14 isotope?

Diagram 14 shows the apparatus set up in an experiment to light up a bulb. What substance can be used as X to light up the bulb?

Diagram 15 shows an electrolytic cell using 2.0 mol dm^-3 sodium chloride solution. What substance is produced at the anode?

Which of the following compounds does not have covalent bonds?

A type of glass has the following properties.

What type of glass is it?

Table 18 shows the pH values of four acidic solutions which have the same concentration.

Which solution has the strongest acidic properties?

Which of the following compounds is acidic?

 $Ammonia\ +\ X\ \rightarrow\ Urea$  

Urea is a nitrogenous fertiliser and can be produced from ammonia by the following reaction. What is substance X?