zt [TNT](zeptotonne)

Zeptotonne (zt) is a unit used to describe a tiny amount of energy, often used within the context of nuclear energy, explosions or other natural events involving the release of energy.

The term "zepto" refers to a prefix indicating a factor of 10^-21, meaning a zeptotonne is equal to one trillionth of a billionth (10^-21) of a tonne. The unit of energy associated with the zeptotonne is typically expressed in tons of TNT, where TNT (trinitrotoluene) is a conventional unit of energy for describing large-scale events like explosions.

So, to understand what is a zeptotonne (zt) of TNT, it's an extremely minuscule unit, equal to 10^-21 tonnes of TNT, representing a very small amount of energy typically demonstrated in nuclear reactions, explosions, or other high-energy events.

Zt [TNT](zettatonne)

Unit Zt or zettatonne of TNT is a unit of energy used in the field of energy to express very large amounts of energy. It is based on the energy released by the explosion of one zettatonne (10^21 tonnes) of trinitrotoluene (TNT).

TNT is a commonly used reference explosive, and its energy content has been standardized for comparing the energy released by different events, such as earthquakes, nuclear explosions, or asteroid impacts. One tonne of TNT is equivalent to approximately 4.184 gigajoules of energy. So, one zettatonne of TNT is equivalent to 4.184 * 10^21 gigajoules of energy. This unit is helpful in expressing and comparing energy values involving large-scale events that release tremendous amounts of energy.

ncal [IT](nanocalorie)

A nanocalorie (ncal) is a unit of energy in the International System of Units (SI) and is equal to one billionth (1 x 10^-9) of a calorie. Specifically, it refers to the International Table (IT) Calorie, which is defined as the amount of heat required to raise the temperature of one gram of water by 1 degree Celsius. In the field of energy, the nanocalorie is a very small unit often used to measure energy at molecular or atomic levels, for instance in the fields of chemistry, physics, or biophysics.1 IT Calorie equals 4.1868 Joules, so 1 ncal equals 4.1868 x 10^-9 Joules.