You are watching: Give the ion notation for an atom with 20 protons and 18 electrons
An ion is a particle that has actually a optimistic or an unfavorable electric charge. A neutral atom becomes a positively fee ion when it loses electrons. A neutral atom becomes a negatively charged ion when it gains electrons.
First, discover F in the periodic table. Its atom number, 9, shows that there room 9 protons and 9 electron in a neutral F atom. Usage the equation E = p - C to calculate the variety of electrons in one F- ion: E = 9 - (-1) = 10 electrons. So, an F - ion has actually 9 protons and 10 electrons.
First, uncover Ba in the routine table. Its atom number, 56, indicates that there space 56 protons and 56 electrons in a neutral Ba atom. Usage the equation E = p - C to calculate the number of electrons in Ba2+ ion: E = 56 - 2 = 54 electrons. So, aBa2+ ion has 56 protons and 54 electrons.
Use the vital for the illustration to identify the proton in the nucleus. There are three protons, for this reason the atom number is 3, which corresponds with lithium (Li). Counting the electrons neighboring the nucleus mirrors two electrons. The algebraic amount of +3 and also -2 is +1, for this reason the ion has a charge of +1, and also the prize is Li+.
Look in ~ the regular table in ~ the back of the book. It shows that one atom that helium (He) includes two protons and also two electrons. Therefore, He can not be the exactly answer. Usage the equation E = ns - C to calculate the variety of electrons in He+:E = 2 - 1 = 1 electron. Therefore, He+ can not be the correct answer. Use the equation to check that He2+ has no electrons: E = 2 - 2 = 0 electrons.
See more: Land Of Nod Bean Bag Zipper Key ? Child Safety Bean Bag Chair Zipper Lock
Begin with the information that the ion has actually 20 protons. This suggests an atomic variety of 20, which corresponds to calcium. The chemical symbol, then, will be Ca. Use the equation E = p - C to calculation the charge on the ion:C = 20 - 18 = 2. The ion has a charge of +2, therefore its chemical symbol is Ca2+.
Chemistry: The main Science14th EditionBruce Edward Bursten, Catherine J. Murphy, H. Eugene Lemay, Matthew E. Stoltzfus, Patrick Woodward, Theodore Brown