Explanation:​
The 6 protons in the nucleus of carbon will exert a stronger attractive force on the second energy level electrons than the 5 protons of boron.
Increasing electron affinity from left to right across a period.

Explanation:​

The names of the labelled groups are covered explicitly in the syllabus.

Explanation:​
C3H6​ belongs to the alkene class with the general formula CnH2n​, and has a three carbon chain.

Explanation​:
A tertiary amine is when three carbon groups are attached to the amine.

Explanation​:
Amides have a C=O and C−N on the same central carbon atom.

Explanation​:
Increasing atomic radius results in a weaker electrostatic force of attraction between the nucleus and electrons in the covalent bond. An increased number of shells down the group increases the shielding between the nucleus and electrons in the covalent bond.

Explanation​:
Statement II is incorrect as acids produce solutions with $\mathrm{pH}$ lower than 7.

Explanation:​
Atomic radius and metallic character decrease across a period. Ionization energy decreases down a group due to increased shielding.

Explanation​:
The longest carbon chain has 5 carbons and will include the C=C.
The alkene is given priority and is on carbon-1.
The methyl group is bonded to carbon-2.

Explanation​:
Saturated compounds contain only single bonds.
Butyne is an alkyne, and so, has a triple bond.

Explanation:​
Across the same period, metals have lower ionization energies than non-metals due to lower nuclear charges with the same number of shells (shielding effect).

Explanation:​
The oxidation state of X in choices A, B, and C is +3. The oxidation state of X in choice D is +6.

Explanation:
Ethers contain C−O single bonds $\text{not}$ the $\mathrm{C}=\mathrm{O}$ carbonyl group.

Explanation​:
Recall that the functional group is carboxyl and the class or series is carboxylic acid.

Explanation​:
NH2​ is the amine functional group, RCOOR′ is the ester functional group.

Explanation​:
Strontium is in group 2 and so forms Sr^2+ ions. The formula of the sulfide ion is S^2− as sulfur is in group 16. For the positive and negative charges to cancel out, one of each ion is required.

Explanation​:
The molecular formula of pentan-2-one is C5H10O

There are 5 C atoms and 10 H atoms, so the combustion produces 5115​ = 5 moles of CO2​ and 102210​ = 5 moles of H2O per mole of pentan-2-one. The value of b is therefore 5.0.

There are $15$ O atoms on the right-hand side of the equation but only 1 O atom in petan-2-one, so the compound must react with (15−1)/2​ = 7 moles of O2​. The value of a is therefore 7.0.

Explanation:​
Statement III is not correct as physical properties, including melting point and metallic character, change dramatically across a period due to changes in nuclear charge for the same number of shells.
Elements in the periodic table are arranged in increased atomic number.
Anions are atoms that have gained electrons. This will increase the electron-electron repulsion in the outermost shell, and will cause the electrons to move further apart. Therefore, the radius of the outershell will increase.

Explanation:
The charges of the positive and negative ions must cancel out to give an overall neutral compound. Group 2 metals form ions with a 2+ charge. The formulae of the counterions above are: NH4+,Cl−,SO4^2−,and PO4^3−

Explanation:​

The atomic number of Cr is higher than that of V by 1, and its relative atomic mass is also higher by approximately 1. The atomic number is unique for each element and dictates the position of the element in the periodic table; thus, Cr always has an atomic number of 24 and vanadium an atomic number of 23. However, isotopes of an element may have different atomic masses, so an atom of Cr may have a lower atomic mass than an atom of V. This question is categorised as easy since the difference between atomic number and atomic mass and the variation in mass between isotopes of an element are covered extensively in the syllabus.

Explanation:​

Elements in the same group (column) of the periodic table have the same number of outer shell (valence) electrons, represented by the group number; the number of electron shells increases down the group. Elements in the same row (period) have the same number of electron shells (or principal quantum number), equal to the period number; the number of valence electrons increases across the period. This question is moderately difficult as the student must recall multiple pieces of information and correctly interpret a schematic illustration of the periodic table.

Explanation:​
Na^+, Ne, O^2−have 10 electrons in two energy levels with 11, 10, and 8 protons respectively. The increased number of protons has a greater pull on the 10 electrons and reduces the radius.
Ca^2+ has 18 electrons in 3 energy levels and is therefore, the largest.

Explanation:​

Lithium is in group 1 and so forms Li+ ions. The formula of the nitride ion is N^3−as nitrogen is in group 15. For the positive and negative charges to cancel out, three Li+ ions are needed for each N^3− ion.

Explanation:

The group of an element is determined by its atomic number, which is found in the lower left corner of the element symbol. Although this conflicts with the representation in the data booklet, students should be able to differentiate between the mass and atomic number based on their relative size. The elements represented by options A, B, C and D are calcium (an alkaline earth metal), iron (a transition metal), gallium (a poor / p block metal) and rubidium (an alkali metal), respectively. This question is moderately difficult as the student must identify the correct value from the given symbol and relate it to the position of an element in the periodic table.