Questions

A term used interchangeably with diskette is Floppy disk.

Microwaves are high-frequency signals in the 300 MHz to 300 GHz range. This is in contrast to radio signals, which are typically broadcast in all directions. Radio signals operate in the 3 Hz to 300 MHz range.

Microwave signals are used for both satellite and ground-based communications.

Mixtures are combination of two or more substances physically which can be separated in to the original.

Matter can be breakdown into two categories. 

1) Pure substances 

2) Mixtures

Here in the given options, options A, B, C are pure substances as they are indicated as S & L in brackets. Option D) is an aqueous solution, that can be dissolved in water.

  Zero. You are selecting names from the list, so they are all listed.

Entropy is a measure of disorder . It will be maximum in gases followed by liquids and least in solids.

Hence, here the gas is only hydrogen and it has the highest entropy.