Learn Unit 1-Matter - Its Nature & Behaviour with Free Lessons & Tips

• It is advisable to use a pressure cooker at higher altitudes because at higher altitudes, the atmospheric pressure is lower, which lowers the boiling point of water. Using a pressure cooker increases the pressure inside the cooker, allowing water to boil at a higher temperature and cook food faster.

• The principle for separation of immiscible liquids is based on the difference in density between the two liquids. When mixed together, the liquids form distinct layers due to their different densities. This allows for the separation of the immiscible liquids by pouring off or decanting the top layer.

• Valency is the combining capacity of an atom, determined by the number of electrons it can gain, lose, or share to achieve a stable electron configuration. Different types of valencies include the positive valency (number of electrons lost), negative valency (number of electrons gained), and covalency (number of electrons shared in a covalent bond).

Valency is the combining capacity of an atom, determined by the number of electrons it can gain, lose, or share to achieve a stable electron configuration. The valency of magnesium is 2, as it loses two electrons to achieve a stable electron configuration, forming the Mg2+ ion. The valency of copper can vary depending on the compound it forms, but its common valencies are 1 and 2.