The metalloids are Boron, Silicon, Geranium, etc and are found to the right of the metals and the left of the nonmetals. Since that is not an option, the best choice would be: The metalloids are located below nonmetals and above metals within a group.
Answer:
(c) P and Sb
Explanation:
We can determine the number of valence electrons of an element:
- If it belongs to Groups 1 and 2, the number of valence electrons is equal to the number of group and the differential electron occupies the s subshell.
- If it belongs to the groups 13-18, the number of valence electrons is equal to: "Number of group - 10" and the differential electron occupies the p subshell.
Which pair of elements have the same valence electronic configuration of np³?
(a) O and Se. NO. They belong to the group 16 and the valence electron configuration is ns² np⁴.
(b) Ge and Pb. NO. They belong to the group 14 and the valence electron configuration is ns² np².
(c) P and Sb. YES. They belong to the group 15 and the valence electron configuration is ns² np³.
(d) K and Mg. NO. They belong to the groups 1 and 2 and the valence electron configuration is ns¹ and ns².
(e) Al and Ga. NO. They belong to the group 13 and the valence electron configuration is ns² np¹.
Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
