Figure 1 shows the dot and cross diagram for a molecule of ammonia - Edexcel - GCSE Chemistry - Question 1 - 2018 - Paper 1

In the dot and cross diagram for ammonia, the dots represent the electrons that are from the nitrogen atom, while the crosses represent the electrons that are contributed by the hydrogen atoms. This visual representation is used to indicate the sharing of electrons in covalent bonding between nitrogen and hydrogen atoms.