Hi, just to improve your answer bit...
1. Li: 1s2 2s1 Ne: 1s2 2s2 2p6
Since both Ne and Li are in the same period, their screening effect is approximate the same. As Ne has more protons than Li, the nuclear charge of Ne is more than Li. Hence electrons are more strongly attracted by the positive nucleus in Ne and therefore more energy is required to remove an electron in Ne than in Li.
2. Na: 1s2 2s2 2p6 3s1 K: 1s2 2s2 2p6 3s2 3p6 4s1
K has more protons than Na resulting in K has higher nuclear charge. However, K has more inner electron shells than Na resulting in its shielding effect is higher, therefore it outweighs the effective nuclear charge, resulting in Na higher IE than K.
hope it helps some..