What element has an atomic weight of 238?

plutonium
Pu-238 is a variant (or isotope) of plutonium with an atomic weight of 238 (94 protons plus 144 neutrons); it was the first isotope of plutonium that was discovered. Some isotopes of a given element, known as radioisotopes, are unstable and decay by emission of energy and particles.

What does atomic weight equal to?

The total weight of an atom is called the atomic weight. It is approximately equal to the number of protons and neutrons, with a little extra added by the electrons. The stability of the nucleus, and hence the atom’s radioactivity, is heavily dependent upon the number of neutrons it contains.

How do you calculate atomic number and atomic weight?

Atomic number: Number of protons present in the nucleus is called atomic number (Z) of an element. Atomic weight: The sum of mass number of proton and mass number of neutron is called atomic weight or atomic mass number (A). Z = 19 and A = 39 as per atomic weight definition.

How do you calculate average atomic mass?

When you are asked to calculate average atomic mass in either chemistry or physics, you look up the atomic mass number of each element on the periodic table, multiply it by the percentage of abundance and then add each of them together. The sum of each element’s mass numbers added together is the total average atomic mass of a group of atoms.

What is the atomic weight of an atom?

An atomic weight (relative atomic mass) of an element from a specified source is the ratio of the average mass per atom of the element to 1/12 of the mass of an atom of 12C. The definition deliberately specifies “An atomic weight…”, as an element will have different relative atomic masses depending on the source.

What is AMU in the periodic table?

The standard atomic weight is the average mass of an element in atomic mass units (“amu”). Though individual atoms always have an integer number of atomic mass units, the atomic mass on the periodic table is stated as a decimal number because it is an average of the various isotopes of an element.

What is atomic number and atomic weight?

Atomic number and atomic weight are two chemical terms that are used to explain the number of subatomic particles present in an atom and its mass. The main difference between atomic number and atomic weight is that atomic number gives the number of protons present in the nucleus whereas atomic weight gives the mass of an atom.