# How do you calculate mass defect?

To calculate the mass defect:
1. add up the masses of each proton and of each neutron that make up the nucleus,
2. subtract the actual mass of the nucleus from the combined mass of the components to obtain the mass defect.
A.

### What does it mean to say that a nuclear equation is balanced?

A balanced nuclear equation is one where the sum of the mass numbers (the top number in notation) and the sum of the atomic numbers balance on either side of an equation.
• #### Which type of nuclear radiation is the most penetrating and why?

There are three types of nuclear radiation: alpha, beta and gamma. Alpha is the least penetrating, while gamma is the most penetrating. Radiation can be harmful, but it can also be useful.
• #### What is the difference between a chemical reaction and a nuclear reaction?

(1) Nuclear reactions involve a change in an atom's nucleus, usually producing a different element. Chemical reactions, on the other hand, involve only a rearrangement of electrons and do not involve changes in the nuclei.
• #### When an alpha particle is emitted from the nucleus of an atom?

When an alpha particle is emitted from a nucleus the nucleus loses two protons and two neutrons. This means the atomic mass number decreases by 4 and the atomic number decreases by 2. A new element is formed that is two places lower in the Periodic Table than the original element.
B.

### What is a decay equation?

For example, carbon-14 is a radioactive isotope of carbon. It decays by beta minus emission. The equation for this decay is: Notice that the atomic mass number is unchanged (because a neutron changed into a proton) and that the atomic number has gone up by one (it has gained a proton).
• #### What is radioactivity simple definition?

radioactivity. The emission of elementary particles by some atoms when their unstable nuclei disintegrate (see half-life). Materials composed of such atoms are radioactive. (See alpha radiation, beta radiation, and gamma radiation.)
• #### What is the alpha decay equation?

For example, carbon-14 is a radioactive isotope of carbon. It decays by beta minus emission. The equation for this decay is: Notice that the atomic mass number is unchanged (because a neutron changed into a proton) and that the atomic number has gone up by one (it has gained a proton).
• #### What happens in an electron capture?

Electron capture is one process that unstable atoms can use to become more stable. During electron capture, an electron in an atom's inner shell is drawn into the nucleus where it combines with a proton, forming a neutron and a neutrino. The neutrino is ejected from the atom's nucleus.
C.

### How is an alpha particle represented in a nuclear equation?

Alpha decay. When an alpha particle is emitted from the nucleus, the nucleus loses two protons and two neutrons. This means the atomic mass number decreases by four and the atomic number decreases by two. A new element is formed that is two places lower in the Periodic Table than the original element.
• #### What happens in the alpha decay of an atom?

Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure below shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus.
• #### Do electrons contribute to the mass of an atom?

When considering atomic mass, it is customary to ignore the mass of any electrons and calculate the atom's mass based on the number of protons and neutrons alone. Electrons contribute greatly to the atom's charge, as each electron has a negative charge equal to the positive charge of a proton.
• #### How does gamma decay differ from both alpha decay and beta decay?

Difference between Alpha, Beta and Gamma radioactive decay can be summarized as follows: Alpha decay forms new element with two fewer protons and two fewer neutrons; Gamma decay forms NO new element, but now the element has less energy because energy is released as gamma rays.

Updated: 2nd October 2019