What do they mean by ideal gas?At a temperature of absolute zero,the volume of an ideal gas is zero. true?

For an ideal (i.e. theoretical) gas, yes...but real gases are not ideal; their atoms have volume.

An ideal gas has particles of zero size and zero mass with no forces of attraction between the particles. At a temperature of 0 K the ideal gas should occupy no volume as all of its zero size particles would have stopped all motion and be in one zero point. No one can know this from experience as absolute zero cannot be achieved. Only by the interpretation of data from as close to 0 K can we predict this. In fact no gas is ideal as all gas particles have size and mass. Their ideal behaviour is seriously affected by this and by the weak van der Waals forces between the particles which become ever more important as the temperature gets lower and the volume decreases. Most gases behave near enough to ideally at high temperatures but no gas is ever really ideal in its behaviour under any conditions.

An ideal gas is a hypothetical substance that would follow all the gas laws perfectly (Boyle's Law, Charles' Law and Gay-Lussac's Law). It assumes gas molecules occupy no space and have no interaction with each other. If all the curves from Charles' Law are extrapolated, they coincide at absolute zero for a volume of zero. Because of the temperature dependence of the volume of a gas, the value of the lowest theoretical temperature can be calculated, where all volumes will be zero. This is absolute zero, which can never be reached.

Basically true. The idea comes from a volume vs temp graph. It is a straight line graph with a positive slope (increases from left to right.) So if the line is extrapolated (extended beyond the data, down and left) to where the volume equals 0, that would be the lowest possible temperature. If you look at http://cnx.org/content/m12598/latest/ , about half way down the page there is a V(mL) vs T(degC) which you can imagine crossing the T-axis at about -273C. Further down is the same data plotted as V(mL) vs T(K). Real gases condense into liquids and V vs T graph becomes almost horizontal. (Compared to gases, the volume of most liquids and solids changes very little as the temp decreases.)

Absolute Zero cannot exist in ANY form, absolute zero can only exist where nothing in sight exists, not light not particles, nothing. there is no suck thing an an Ideal gas volume period. The only comment that can be asked to prove me wrong is "Prove that absolute zero exists", Focus on results not words.

An ideal gas is a convenient little tool physicists came up with so they don't have to account for the mass of gaseous molecules when doing calculations. It's less accurate but generally it's considered to be worth the drop in accuracy.