What is plasma?

Plasma can mean one of two things.

Asked by Francis Mendez

Plasma can actually mean two different things in science. In biology, plasma is the straw-coloured liquid component of our blood. It is the liquid that all our red and white blood cells, alongside platelets and nutrients, are carried in.

Plasma also refers to the fourth state of matter which exists alongside solid, liquid and gas. Plasma is similar to a gas but in plasma the atoms are ionised. Ionisation means that some of the negatively charged electrons are separated from the atom. This gives the remaining atom an overall positive charge, while the separated electrons have a negative charge. This type of plasma exists in neon signs and stars like the Sun.

Lisa Rainsley, Science Museum