In physics, energy density is the amount of energy stored in a given system or region of space per unit volume. It may also be used for energy per unit mass, though a more accur...

Energy density is the amount of energy in a given mass (or volume) and power density is the amount of power in a given mass. The distinction between the two is similar to the di...

The 324 metres tall Eiffel Tower not only becomes hotter in summer, but it also becomes taller. This is due to thermal expansion in the iron structure. When heated, the iron par...

The liver is classed as a gland. This vital organ carries out more than 500 roles in the human body. It is the only organ that can regenerate. The liver is the largest solid org...

Heterocrine glands are the glands which act both as exocrine and endocrine glands. Exocrine glands are the glands that produce their products via the ducts while endocrine gland...

Plasmolysis is when plant cells lose water after being placed in a solution that has a higher concentration of solutes than the cell does. This is known as a hypertonic solution...

Objects deform when pushed, pulled, and twisted. Elasticity is the measure of the amount that the object can return to its original shape after these external forces and pressur...

Molecular solids—Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. ... Metallic solids—Made up of met...

Vocal sounds are made by a special organ only birds possess: the syrinx. The syrinx is located at the very top of the birds' windpipe. The air that comes in through the windpipe...