Question

Determine the Z and A numbers for an atom with 20 protons, 19 neutrons, and 18 electrons. What element would this be in the periodic table? Is this an atom or an ion? If an ion, what is the charge on it?

Answer 1

The atom has an atomic number of 20 and a mass number of 39. The element is calcium (Ca) on the periodic table. It is a neutral atom with 20 protons and electrons.

Step-by-step explanation:

The atomic number (Z) of an atom is determined by the number of protons in its nucleus. In this case, the atom has 20 protons, which means its atomic number is 20.

The mass number (A) of an atom is determined by the total number of protons and neutrons in its nucleus. In this case, the atom has 20 protons and 19 neutrons, so its mass number is 39.

The element with an atomic number of 20 is calcium (Ca) on the periodic table. Since the atom has the same number of protons and electrons (20), it is a neutral atom and not an ion.