Video Transcript
Which of the following statements correctly states a similarity between arsenic and antimony? (A) They are both more abundant in Earth’s crust than phosphorus. (B) They are both metalloids. (C) They both contain four electrons in their last p orbital. (D) They are both less dense than nitrogen. (E) They both form diatomic molecules under standard conditions.
Let us begin by looking at each answer choice to identify the similarities between arsenic and antimony. Let us first investigate the abundance of the group 15 elements. When looking at the group 15 elements, the abundance of these elements decreases going down the periodic table. As we can see, arsenic and antimony represented by As and Sb, respectively, are less abundant than phosphorus represented by P. Since phosphorus is more abundant than arsenic and antimony, answer choice (A), they are both more abundant in Earth’s crust than phosphorus, is the incorrect answer choice.
Now, let us investigate the density of the group 15 elements. When looking at the group 15 elements, nitrogen is in the gaseous state, whereas arsenic and antimony are solids and therefore more dense. Therefore, answer choice (D), they are both less dense than nitrogen, is the incorrect answer choice. Now, let us take a look at option choice (E). There are seven diatomic elements within the periodic table, hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. Therefore, option choice (E), they both form diatomic molecules under standard conditions, is the incorrect answer choice.
Now, let us take a look at the periodic table to investigate answer choice (C): they both contain four electrons in their last p orbital. Elements in group 15 actually have five electrons in their valence shell. The first two electrons are in the s orbital. The last three electrons are in the p orbital. Therefore, option choice (C), they both contain four electrons in their last p orbital, is the incorrect answer choice.
Now, let us take a look at option choice (B). There are seven metalloids within the periodic table, boron, silicon, arsenic, tellurium, astatine, germanium, antimony, and polonium. When looking at the metalloids, we should note that both arsenic and antimony are in group 15. Therefore, option choice (B), they are both metalloids, is the correct answer choice for a similarity between arsenic and antimony.
