Luminous intensity is a measure of the radiant power emitted by an object in a given direction, and is dependent on the wavelength of light being emitted. It is weighted to the sensitivity of the human eye, by what is called the "standard luminosity function". The SI unit for luminous intensity is the candela which has an operational definition. This means it is defined by a set wavelength of light emitting a specific amount of power.

Reducing sugar is a saccharide that is capable of acting as a reducing agent because it has a free aldehyde or ketone group. The most important monosaccharides, glucose and fructose, act as reducing agents in alkaline solution. They react with Fehling's solution by reducing the copper (II) ions to copper (I) oxide. When Benedict's reagent solution and reducing sugars are heated together, the solution changes its colour to orange-red/ brick red. This colour is due to the presence of simple carbohydrates. In specific, the copper (II) ions in Benedict's solution are reduced to Copper (I) ions, which causes the colour change.

Soda ash, also known as sodium carbonate, is an inorganic compound with the formula Na₂CO₃ and its various hydrates. All forms are white, water-soluble salts. All forms have a strongly alkaline taste and give moderately alkaline solutions in water. Historically, it was extracted from the ashes of plants growing in sodium-rich soils and used in the manufacture of different products.

Marie Curie became the first woman to be awarded the Nobel Prize and the first person to obtain two Nobel prizes when she won the prize for the discovery of Polonium and Radium in 1911. Though it was Henri Becquerel that discovered radioactivity, and it was Marie Curie who coined the term.

Hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Robert Boyle produced hydrogen gas in 1671 while he was experimenting with iron and acids, but it wasn't until 1766 that Henry Cavendish recognized it as a distinct element, according to Jefferson Lab. The element was named hydrogen by the French chemist Antoine Lavoisier.

 When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection. The fluid above a hot surface expands, becomes less dense, and rises. Warm water around the equator circulates towards the poles and the cooler water at the poles moves towards the equator. This happens due to convection.

Louis de Broglie was a French physicist who made groundbreaking contributions to quantum theory. In his 1924 PhD thesis, he postulated the wave nature of electrons and suggested that all matter has wave properties. This concept is known as the de Broglie hypothesis, an example of wave–particle duality, and forms a central part of the theory of quantum mechanics. He was the first man to predict the interrelationship of matter and energy.

Maharaja Ranjit Singh was the leader of the Sikh Empire, which ruled the northwest Indian subcontinent in the early half of the 19th century.In July 1799 he seized Lahore, the capital of Punjab. The Afghan king, Zaman Shah, confirmed Ranjit Singh as governor of the city, but in 1801 Ranjit Singh proclaimed himself maharaja of the Punjab.

Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and whites of the eyes due to high bilirubin levels. Jaundice may be caused by several different disease processes. It is helpful to understand the different causes of jaundice by identifying the problems that disrupt the normal bilirubin metabolism or excretion.

Physical changes involve states of matter and energy. No new substance is created during a physical change, although the matter takes a different form. The size, shape, and color of matter may change. Physical changes occur when substances are mixed but don't chemically react. Melting of ice-cube is an example of physical change.