Questions

When water is cooled from 4°C to 0°C, its density decreases.

When water cools from 4°C to 0°C, ice crystals begin to form because the water is approaching its freezing point. When water freezes, the water molecules form a lattice that increases the volume. As a result, the density decreases. This is why ice will float on top of water; ice has a lower density than the water.

The term for classifying and grouping organisms is Taxonomy. It is the science of defining and naming groups of biological organisms on the basis of shared characteristics.

The struggle for Italian independence and unification was organised by the two famous revolutionaries of Italy Giuseppe Mazzini and Giuseppe Garibaldi. The movement led by them is known as the 'Young Italy' movement. It aimed at the independence and unification of Italy and the establishment of republic there.

The sound is what can you hear but not touch or see.

Zoroastrianism is one of the world's oldest extant religions. It is the ancient pre-Islamic religion of Iran that survives there in isolated areas and, more prosperously, in India, where the descendants of Zoroastrian Iranian (Persian) immigrants are known as Parsis, or Parsees.

The Iranian prophet and religious reformer Zarathustra flourished before the 6th century BCE more widely known outside Iran as Zoroaster is traditionally regarded as the founder of the religion.

Zoroastrianism contains both monotheistic and dualistic features. It likely influenced the other major Western religions—Judaism, Christianity, and Islam.