1c) Gallium has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1: lowest energy level is the one which is nearest to the atom’s nucleus and that is s subshell of quantum shell 1. Highest energy level is in quantum shell 4 and has p subshell with only 1 electron.

CIE A Level Chemistry Solved Past Paper Feb/March 2019 P22

1 aiii) Ionisation energy is energy required to remove an electron from a gaseous atom’s outermost shell. When nucleur attraction increases, ionisation energy increases and nucleur attraction increases when number of electrons increase and shielding effect remains same.

1 ai) Subatomic particles of an atom are protons, neutrons & electrons. Isotopes are atoms of same element with same number of protons but different number of neutrons.

1 ai) Oxidizing agents bring oxidation to other species in the reaction and get reduced themselves. In this Q, MnO2 is the oxidizing agent which oxidizes Cl- ion from -1 to 0 and gets reduced from +4 to +2. b) Volatility is a property which explains how fast a substance vapourizesmand it decreases down goup VII. Vapourization is quicker at…

CIE A Level Chemistry (9701) Solved Past Paper May/June 2019 P23

CIE A Level Chemistry (9701) Solved Past Paper May/June 2019 P21

CIE A Level Chemistry Solved Past Paper May/June 2019 P22