A part of the periodic table is shown. 3 Li 4 Be
11 Na 12 Mg
19 K 20 Ca

Which of the following elements is less reactive than the others?

Select one:
a. Beryllium (Be)
b. Calcium (Ca)
c. Lithium (Li)
d. Magnesium (Mg)

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

This flow chart shows the amount of energy that is emitted by each type of light. ultraviolet > blue light > yellow light > red light (maximum energy) (minimum energy) in an experiment, shining which type of light on a strip of metal would be least likely to produce the photoelectric effect? ultraviolet light dim blue light bright red light bright yellow light

Ineed to find the answer of this question because i dont understand it