a single atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it?\n○ k\n○…

a single atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it?\n○ k\n○ zr\n○ ca\n○ sc

a single atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it?\n○ k\n○ zr\n○ ca\n○ sc

Answer

Brief Explanations:

To identify the element, we use the fact that the number of protons (atomic number) determines the element. The atom has 20 protons, so the atomic number is 20. Calcium (Ca) has an atomic number of 20. Let's verify other options: K (potassium) has atomic number 19, Zr (zirconium) has atomic number 40, and Sc (scandium) has atomic number 21. So the element with 20 protons is Ca.

Answer:

Ca (Calcium)