Why do they have same atomic number but different atomic masses?

Those elements that have the same atomic number but a different mass number are referred to as isotopes. Isotopes occur due to the presence of a different number of neutrons in elements having the same atomic number as mass number is the sum of the number of neutrons and protons.

Why is the mass of a nucleus always less than the sum of the masses of its constituents?

In the case of nuclei, the binding energy is so great that it accounts for a significant amount of mass. The actual mass is always less than the sum of the individual masses of the constituent protons and neutrons because energy is removed when when the nucleus is formed.

Has a mass that is equal to the sum of the masses of its protons and neutrons?

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit (amu). By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom.

Why relative atomic masses are used rather than actual masses of atoms?

An atom’s mass number can never be smaller than its atomic number, and while it can be the same it is normally larger. We use the relative atomic mass of an element as opposed to its actual mass, because the actual mass is very small.

Which element has the same atomic mass but different atomic number?

Isobars
Isobars: The elements which have the same atomic mass but different atomic number, are known as isobars. For example: Argon and calcium. They both have atomic mass 40 but atomic number of argon is 18 and atomic number of calcium is 20.

What is the relation between atomic number and mass number?

The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. In other words, the number of neutrons in any atom is its mass number minus its atomic number. Although all atoms of a given element must have the same atomic number, they need not all have the same mass number.

What does the ejection of an alpha particle from a nucleus results in?

These alpha particles are tightly bound units of two neutrons and two protons each (He4 nucleus) and have a positive charge. Emission of an alpha particle from the nucleus results in a decrease of two units of atomic number (Z) and four units of mass number (A).

Why atomic mass is the sum of protons and neutrons?

Why is the mass of a carbon atom greater than the total mass of its protons and electrons?

Differing numbers of neutrons give rise to the existence of isotopes. For Z=6 , the element is C ; i.e. there are 6 massive, positively charged protons in each C nucleus by definition. A small number of C atoms have 7 neutrons in their nuclei, i.e. 13C ; a smaller number have 8 neutrons to give the 14C isotope.

Why is the atomic number better than the atomic mass?

Why is the atomic number better than the atomic mass for organizing the elements in the periodic table? The atomic number defines the element given. It will always be the same for each specific element. The atomic mass is a weighted average of the isotopes of an element.

Why do we compare relative atomic mass to carbon-12?

Atomic mass is based on a relative scale and the mass of 12C (carbon twelve) is defined as 12 amu; so, this is an exact number. Why do we specify 12C? Each carbon atom has the same number of protons and electrons, 6. 12C has 6 neutrons, 13C has 7 neutrons, and 14C has 8 neutrons and so on.

Why is the energy of nuclear fission greater for medium-mass nuclei?

Figure 2 shows that BE/ A is greater for medium-mass nuclei than heavy nuclei, implying that when a heavy nucleus is split, the products have less mass per nucleon, so that mass is destroyed and energy is released in the reaction. The amount of energy per fission reaction can be large, even by nuclear standards.

What happens in a nuclear fission chain reaction?

In a U-235 fission chain reaction, the fission of the uranium nucleus produces high-energy neutrons that go on to split more nuclei. The energy released in this process can be used to produce electricity. View a simulation on nuclear fission to start a chain reaction, or introduce nonradioactive isotopes to prevent one.

Does fission of a given nuclide always produce the same product?

Fission of a given nuclide, such as 238 U , does not always produce the same products. Fission is a statistical process in which an entire range of products are produced with various probabilities.

What is it called when an atomic nucleus is broken apart?

Summary of the type, nuclear equation, representation, and any changes in the mass or atomic numbers for various types of decay. Occasionally, an atomic nucleus breaks apart into smaller pieces in a radioactive process called spontaneous fission (or fission). Typically]