Entri Career Fest- Up to 50% Off on In-demand Courses ✦ 12,000 Government Jobs Secured ✦ 5,000+ Private Job Placements ✦ 4.9 ⭐️ Google Play Store Rating✦ +++

Get Ahead with Our Exam Q&A

Explore our extensive collection of questions and answers to enhance your learning experience and prepare for exams effectively

The atomic number of calcium is 20. That is around the nucleus of calcium 20 electrons revolve in various shells. The electrons are filled in various orbits or shells in the increasing order of their energy. According to Afbau’s principle, first two electrons filled in the lowest energy level K then 8 electrons in the next higher energy level L. The maximum capacity of next shell, that is M is 18 but the remaining 10 electrons of sulphur not entered in to M shell due to octet rule. Therefore out of 10, 8 electrons entered into M, the remaining 2 electrons entered into N shell.

Some animals use echos, sound waves reflected off objects in their path ,to navigate and find food at night or in dark locations such as caves. This is known as echolocation.

Echolocation, also called bio sonar, is a biological sonar used by several animal species.
Eg: Bats. Dolphines, Whales, etc.

?Optical density is the measure that shows how a medium influences the speed of light passing through it. If the optical density of a medium increases, the speed of light through it decreases.

Change in direction of light when light passes from one medium to another is called REFRACTION OF LIGHT.

EG: Twinkling of stars, mirage in desert

Surface tension is the property of a liquid by virtue of which, the surface of a liquid acts like a stretched membrane thereby acquiring the least possible surface area.
- This property is attributed to the cohesive forces between the molecules of the liquid. The stronger the cohesive force, the stronger the surface tension.
- Surface tension depends on the nature of the liquid, the surrounding environment and temperature.

Ozone is a monoatomic element.
Ozone is an element formed by combining three oxygen atoms.
Glucose is a compound of carbon, hydrogen and oxygen.
Water is a compound formed by combining two hydrogen and one oxygen atom.
Alumima is a compound formed by combining two aluminium and three oxygen atoms.

The three nucleur radiations are alpha particles, beta particles and gamma rays.
X-rays are an example of electromagnetic radiation.
Alpha particle or alpha ray consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.
Beta radiation, is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay.
Gamma ray, electromagnetic radiation of the shortest wavelength and highest energy.

Gold is the most malleable metal and he wanted the thinnest layer as possible.
Platinum is the most ductile metal. Gold, silver and platinum are inert metals.
Silver has the highest electrical conductivity.
Using this experiment Rutherford states that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.
Based on these results, Rutherford proposed the nuclear model of the atom.

Dalton proposed atomic theory. Atomic theory is the scientific theory that matter is composed of small minute particles called atoms. The word atom derived from a Greek word atomos means uncuttable. Atoms of different elements combine in fixed ratio to form compounds. According to theory atoms of same elements have same mass and properties and atoms of different elements have differnt mass and properties.

Kidney excretes the toxic substance ammonia from the body as urea , uric acid and ammonia .
In human beings and mammals ammoia is excreted as urea and is called Ureotelic.
In birds and reptiles ammonia is excreted in the form of uric acid and they are called Uricotelic.
In fishes and frogs it excreted as ammonia itself and is called Ammontelic.

Get Expert Advice for Free: Register for Your Free Consultation Now!

Full Name

Phone Number

Select Language

Select Course

[honeypot honeypot-100]