Question 14 of 30 Which of the following elements has 1 valence electron?
The Periodic Table
A. Sodium (Na)
B. Chlorine (CI)
C. Calcium (Ca)
D. Helium (He)
SUBMIT

A. Sodium (Na)

Explanation:

The total number of electrons in the outermost principal energy level of an element is called the valence electrons of that element.

Na (11)---→1s2 2s2 2p6 3s1

There 1 electron in the outermost principal energy level of Sodium. So, the number of valence electron of Sodium is 11.

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later

It was ernest rutherford