Question

periodic table place the elements in order from the element with the most electrons to the element with the least number of electrons. h se ar ca

Explanation:

Step1: Find atomic numbers (electrons = protons = atomic number)

• H (Hydrogen): Atomic number 1 → 1 electron.
• Se (Selenium): Atomic number 34 → 34 electrons.
• Ar (Argon): Atomic number 18 → 18 electrons.
• Ca (Calcium): Atomic number 20 → 20 electrons.

Step2: Order by number of electrons (most to least)

Compare 34 (Se), 20 (Ca), 18 (Ar), 1 (H). So order: Se, Ca, Ar, H.

Answer:

Se, Ca, Ar, H