question 17\nwhich of the following elements belongs to the p - block?\n○ cobalt\n○ hydrogen\n○ rubidium\n○…

question 17\nwhich of the following elements belongs to the p - block?\n○ cobalt\n○ hydrogen\n○ rubidium\n○ oxygen\n\n1 pts\nquestion 18\nhow many valence electrons are found in gallium?\n○ 1\n○ 5\n○ 3\n○ 7

question 17\nwhich of the following elements belongs to the p - block?\n○ cobalt\n○ hydrogen\n○ rubidium\n○ oxygen\n\n1 pts\nquestion 18\nhow many valence electrons are found in gallium?\n○ 1\n○ 5\n○ 3\n○ 7

Answer

Brief Explanations:

For Question 17: Elements in the p - block have their outermost electrons in p - orbitals. Oxygen has its outer - shell electrons in p - orbitals and is in Group 16 (p - block). Cobalt is a d - block element, hydrogen is in the s - block, and rubidium is in the s - block. For Question 18: Gallium has an atomic number of 31. Its electron configuration is [Ar]3d¹⁰4s²4p¹. The valence electrons are the electrons in the outermost shell, which are 4s²4p¹, so there are 3 valence electrons.

Answer:

Question 17: oxygen Question 18: 3