Secondary 1 Term 2 Science ACE Project

Secondary 1 Term 2 Science ACE Project

Secondary 1 Term 2 Science ACE Project:

PLASMA

By: Jerroy Chang (4) of 1I3

What is plasma?

Plasma is known as the fourth state of matter, apart from the three basic states, solid, liquid and gas. Plasma is, in simple terms, ionized gas. It is mainly exciting a gas until it breaks up into individual atoms, and some of those atoms lose their electrons, turning into positive ions. These electrons and positive ions both make up plasma. The excitement of the gas uses energy, which can come in 3 forms: thermal, electrical, or light.

Origin:

The first scientist who found this fourth state of matter is Sir William Crookes, a British chemist, in 1879. He found plasma in his own invented tube, the Crookes tube. Later, in 1929, Dr. Irving Langmuir, an American chemist, declared that fourth state of matter as “Plasma”.

Plasma and the Universe:

Plasma is the most common form of matter. It makes up over 99% of the visible universe. Plasma can be found in the stars and the space between planets and stars, such as our Sun.

Plasma particles:

Properties of plasma:

Plasma is a good conductor of electricity.

Plasma is affected by magnetic fields.

Uses of plasmas

Plasma is used in fluorescent tubes. Electricity excites the mercury vapor in the tube, and therefore ionization occurs, leading to the change in state from gas to plasma. Therefore, the mercury vapor gives off a white glow. Plasma can also be found in neon signs, where noble gases such as neon, krypton and xenon are excited to form different colours.Plasma displays are another way plasma is used, such as in plasma TVs, when varying electrical volts excite gases to turn into different colours, creating an image on the screen.

Where else are plasmas found?

St. Elmo’s fire is another place where plasma can be found. St. Elmo’s fire is a mix of gas and plasma. An electric field excites the air molecules, producing a faint glow around objects.

Plasma can also be found in the aurora at the Northern and Southern poles. The ionized gas is funneled down the Earth’s magnetic field lines. After that, they will emit a photon of light, thus causing the aurora.

Electric arcs are also another form of plasma that results when an electric current is flowing through the air, exciting the air and effectively ionizing it. Therefore, plasma forms in the gap between the wires.

Lastly, plasma can be found in stars such as our Sun, solar wind, nebulas and space.

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