NTSE (Science) - 1

Momentum is defined as the product of mass and velocity. Since velocity is a vector quantity, momentum is also a vector quantity.

Venus is the hottest planet in the solar system due to its dense atmosphere, which traps heat through a runaway greenhouse effect, despite Mercury being closer to the Sun.

Allotropes are different physical forms of the same element. Diamond and graphite are both naturally occurring forms of pure carbon.

LPG (Liquefied Petroleum Gas) is primarily composed of propane and butane. While both are constituents, propane is often cited as a major component in many standard mixtures.

Potassium (K) is an alkali metal that is very soft and can be easily cut with a knife. Aluminum, calcium, and iron are much harder metals.

Erythrocytes, or red blood cells, contain hemoglobin, which is the protein responsible for binding and transporting oxygen in the blood.

An endothermic reaction is a chemical reaction that absorbs heat energy from its surroundings, resulting in a decrease in temperature.

Photolysis is the process where light energy is used to split water molecules into oxygen, protons, and electrons during the light-dependent reactions of photosynthesis.

Asthma is a respiratory condition marked by spasms in the bronchi of the lungs, causing difficulty in breathing.

The water vascular system, or ambulacral system, is a unique network of water-filled canals found in echinoderms like the starfish, used for locomotion and feeding.

Parkinsonism is a progressive disorder of the nervous system that affects movement, originating from the degeneration of neurons in the brain.

Scientific consensus estimates the age of the Earth to be approximately 4.54 billion years, which is commonly rounded to 4.6 billion years in textbooks.

Work done is defined as W = F * d * cos(theta), where F is force, d is displacement, and theta is the angle between them. Therefore, it depends on all three factors.

Cereal crops, such as wheat, rice, and maize, are primary sources of carbohydrates in the human diet.

Frequency (f) and time period (T) are inversely related by the formula f = 1/T. If the time period increases, the frequency must decrease.

Rice is the most widely consumed staple food and the principal cereal crop in India.

Thermosetting plastics are polymers that form cross-linked structures during curing, making them insoluble and infusible. They do not dissolve in common solvents like water, ether, or benzene.

When reactive metals (like sodium or potassium) react with water, they displace hydrogen, resulting in the liberation of hydrogen gas.

The SI unit of energy is the Joule, which is defined as the work done by a force of one newton over a distance of one meter. Watt hour is a unit of energy, but it is not the SI unit.

German silver (also called nickel silver) is primarily an alloy of copper (50-70%), nickel (10-30%), and zinc (10-35%). Despite its name, it contains no actual silver. The copper is the base metal, making option B the best answer among the choices.