51
zirconium
Each isotope of an element has a different number of neutrons.
The element you are referring to is Zirconium (Zr), which has an atomic number of 40 and is located in period 5 of the periodic table. Since Zirconium has 40 protons, having 51 neutrons gives it an atomic mass of approximately 91 (40 protons + 51 neutrons). This places it specifically as the isotope Zirconium-91.
Zirconium has 40 electrons and protons; the number of neutrons is specific for each isotope. Number of neutrons in a zirconium isotope = Mass number - 40
The number of neutrons for any given element varies, depending on the isotopes. Search the Wikipedia, or Google, for "Isotopes of Zirconium" for the isotopes of this particular element. The list of isotopes will give you the atomic mass (protons + neutrons) for the different isotopes; subtract the atomic number (which is the number of protons) to get the number of neutrons for each isotope.
The isotope of zirconim, 91Zr, has 51 neutrons. In order to solve this problem, one must know that an element's atomic weight is the average of its number of protons and neutrons (only neutrons are variable). Since the atomic number is the number of protons, the atomic number subtracted from the atomic weight gives the number of neutrons. An element in period 5 that has this many neutrons is found to be zirconium (the isotope 91Zr).
Each isotope of an element has a different number of neutrons: Atomic mass of the isotope - Atomic number = Number of neutrons
AnswerThere are 40 protons in the element "zirconium". There are a number of isotopes of Zr, with the most common having an atomic weight (protons plus neutrons) of 90, with 94 and 92 tied for second place. That leaves 50 neutrons as most common, with 52 or 54 neutrons as alternatives.
Zirconium is a metal element. There are 40 electrons in a single atom.
An atom's atomic number gives its number of protons. Zirconium's atomic number is 40. Thus it has 40 protons in each atom, regardless of isotope.
Zirconium is a chemical element with the symbol Zr and atomic number 40. It has 40 protons and typically 40 neutrons in its nucleus, giving it an atomic mass of about 91u. Zirconium is a lustrous, gray-white, strong transition metal that is commonly used in nuclear reactors and various industrial applications.
Zirconium has 40 protons and typically 51 neutrons in its nucleus, giving it a mass number of around 91. The protons are positively charged particles while the neutrons are neutral, together making up the nucleus of the zirconium atom.