Question

#7) The atom on the left (pink) in the video is shown in the diagram below. From

Answer 1

Answer:

             A

Explanation:

                    Remember the number of valence electrons represent the group number. As shown in figure, there is only one electron in the valence shell. Therefore, this element belongs to group 1 elements also called as Alkali metals.

Furthermore, the number of electrons in a neutral atom equals number of protons. Hence, there are 11 protons in this element.

Also, number of protons equal atomic number therefore, the atomic number of this element is 11. And, by checking periodic table, the element having atomic number 11 is Sodium (Na).