What is Plasma?

A plasma (or, more properly, an electromagnetic plasma) is a phase of matter that has enough energy for the electrons to separated from the nucleus. It consists of independently moving electrons and nuclei, and thus has some rather interesting properties, such as very good magnetic shielding. It can be found in places such as the center of the sun, and also, in small quantities, surrounding a lightening bolt. 

Many people consider solid, liquid, gas and plasma to be the only four phases of matter. This is not true, as there exist many others, but they are generally more exotic with names like hadron gas or Bose-Einstein Condensate.

How did atom obtain its name?

The word is derived from the Greek word "atomos", meaning indivisible. The concept of the atom originated round 440 BC. In Greek, the prefix "a" means "not" and the word "tomos" means cut. Word "atom" therefore comes from "atomos", a Greek word meaning uncuttable. 

In 1803, John Dalton formulated the "atomic theory" of matter based on experiments that quantified the weights of elements formed when compounds were broken down. Based on experimental evidence, Dalton proposed that atoms really do exist as fundamental units of all elements. 

Twentieth century physics was able to probe atoms and prove that they are not, in fact, indivisible. But the name stuck, and still has meaning in that atoms are the smallest, indivisible part of any element. If you do divide them into smaller pieces of protons, neutrons and electrons, you no longer have the original element.

What is Dry Ice?

Dry ice is nothing but solidified Carbon Dioxide (CO₂). When Carbondioxide is cooled to a very low temperature it transforms into solid. The  temperature is about -78 deg centigrade. 

Carbon Dioxide is an interesting material because, at normal atmospheric pressures, it has no liquid state. It can only obtain a liquid state under very high pressure in a containment vessel.

So, when you have a frozen chunk of carbon dioxide out in the open where you can see it, it will transform directly from its solid state to a gas state with no intermediate liquid state. This process is known as 'sublimation'.

Dry ice freeze water vapor in the air near it producing visible vapor all by itself, however adding water will also add substantial heat which will cause the solid CO₂ to sublimate at a greatly accelerated rate thus producing much more visible vapor.

What is Heavy water?

Normal water is made of two Hydrogen atoms and one Oxygen atom. Hydrogen atom and Oxygen atoms are covalently bonded together. Normal water is designated by H₂O.

Heavy water also has same molecular structure but Hydrogen atoms are replaced by isotopes of Hydrogen called 'Deuterium'. Standard hydrogen has one Proton in its nucleus (Relative Molecular Mass = 1), Deuterium has one Proton and  one Neutron in it nucleus, (Relative Molecular Mass = 2). Hence it is 'heavier' than normal hydrogen. This leads to the water being heavier.

What is Boyles Law?

Boyle's Law is a statement of the relationship between the pressure and volume of gasses. Specifically it states that under isothermic conditions, i.e. when temperature remains constant, the product of the pressure and volume remains constant, or

P₁ x V₁ = P₂ x V₂

where P₁ is the pressure before some change, V₁ is the volume before the change, P₂ and V₂ are the new values after the change.

What are the differences between jet airplanes and rockets?

Newton's third law of motion holds good for motion of both jet air planes and rocket engines. They move by expelling hot gases opposite to the direction of desired acceleration. The momentum imparted to the gases is exactly opposite to the momentum imparted to the vehicle.

The biggest difference between a jet engine and a rocket lies in their propulsion systems.

 A jet engine works like this: It sucks in air from the front of the engine. This air is burned with the fuel within the engine. The resulting large mass of gas is ejected towards the rear at high velocity, which both propels the airplane forward, and gets more air sucked into the engine. In normal flight, the engines are used to propel the airplane forward. The actual 'uplift' is gained through the wings using the strong flow of the wind. 

A rocket, in contrast, carries both fuel (which may be solid or liquid) and oxygen. Therefore it does not suck in air from the front. All it does is burn the fuel with the oxygen, and eject it at very high velocities backward. This momentum is used to both lift and propel the rocket. There are no wings for uplift. Any wings are for steering purposes. 

In a nut shell, rocket carries its own supply of oxygen for combustion. A jet engine requires oxygen from the atmosphere for combustion, and so cannot operate in the vacuum of space.