Oxygen reacts 1:2 with sodium and is a colourless gas; chlorine reacts 1:1 with sodium and is a yellow gas; neon does not reacts with sodium and is a colourless gas. Suppose that a new element , pretendium, has been dicovered, and it is noted that this element reacts 1:1 with sodium and is bright green as a gas.
A) which chemical family would it belong to?
-I think halogens.
B) How many electrons would it have in its outermost shell?
-7?
A) Pretendium would not belong to the halogens. It would actually belong to the group of elements known as the alkali metals. This is because it reacts 1:1 with sodium, just like chlorine, which is an alkali metal.
B) Since pretendium belongs to the alkali metals group, it would have only 1 electron in its outermost shell. The alkali metals have a valence electron configuration of ns1, where "n" represents the energy level of the outermost shell.
To determine the chemical family and the number of electrons in the outermost shell of the new element, pretendium, we need to analyze its reaction with sodium.
A) To determine the chemical family, we compare the reaction of pretendium with sodium to the reactions of known elements. Pretendium reacts 1:1 with sodium, just like chlorine. Chlorine belongs to the halogen family, which consists of elements that react with metals in a 1:1 ratio. Therefore, it is reasonable to conclude that pretendium would also belong to the halogen family.
B) Now, to determine the number of electrons in the outermost shell (valence electrons), we look at the periodic table. Since pretendium belongs to the same chemical family as chlorine, which is in group 17 (Group VIIA or the halogen group), we know that both chlorine and pretendium have seven valence electrons. Elements in group 17 have an electron configuration of ns^2 np^5, where n represents the highest energy level. Therefore, it can be inferred that pretendium would also have seven electrons in its outermost shell.
So, the answer is:
A) Pretendium would belong to the halogen family.
B) Pretendium would have seven electrons in its outermost shell.