Number of neutrons = mass number - atomic number = 40 - 19 = 21 answer
Answer:
Cs and I
Explanation:
Salts are formed when an ionic bond is formed between two elements in the compound. Let us recall that the kind of bond formed between any two elements depends on the magnitude of electronegativity difference between the two elements.
Among the options listed, the highest degree of electronegativity difference occurs for the bond between Cs and I. This implies that this bond is ionic and the combination of the two elements will lead to salt formation.
It benefits of the solar radiation for out planet is that it gives us heat, natural sunlight and its pollution free.The disadvantage for solar radiation is that there are also some toxic materials and hazardous products used during the manufacturing process of solar photovoltaic systems, which can indirectly affect the environment.
Hope I helped^^
