Questions

XPath is an expressions to select a xml node in an XML document.

It allows the navigation on the XML document to the straight to the element where we need to reach and access the attributes.

The photoelectric effect pointed to the particle properties of light, which had been considered to be a wave phenomenon. Particles like electron and protons have both particle like and wave like behavior. Thus, according to de Broglie, all the material particles in motion possess wave characteristics. Although the dual nature of matter is applicable to all material objects but it is significant for microscopic bodies only.

A tone in music is a sound that has definite pitch. Pitch is nothing but the relative highness or lowness of a sound.

Biotin is a water-soluble B vitamin, also called vitamin B7 and formerly known as vitamin H or coenzyme R.