Non-reactive elements do not easily combine with the other elements. Helium, neon, and argon are examples of very non-reactive elements. A measure of substance equivalents that are dissolved in a volume of solution. Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Therefore, noble gases have eight valence electrons. Helium and neon atoms have completely filled outermost electron shells (containing the maximum number of electrons which can be accommodated in them).

Reflex action is the extremely quick, automatic, sudden action in response to something in the environment.

Example- i) Immediately pulling back of fingers after touching a hot plate.

ii) Closing of eyes when flashed with high intensity light.

iii) Salivation when hungry.

• Pituitary gland: Enclosed deep within the skull, the pituitary gland is the size of a pea. It hangs on a stalk at the base of the brain. It consists of an anterior portion that produces hormones and a posterior portion that has many neural links. This gland is regarded as the master gland as it controls the functions of all the other glands (such as the adrenal, thyroid glands) in the endocrine system. The pituitary gland stimulates the adrenal gland to secrete cortisol, a steroid hormone controls a range of activities from controlling the body’s metabolism to stimulating blood pressure. The pituitary gland also secretes prolactin, which stimulates the production of milk.
• Thyroid gland:The thyroid glands can be found at the front of the neck. It sits low in the throat, between the windpipe. Brownish red, it has blood vessels coursing through it. It secretes hormones that are collectively called thyroid hormones. The most prominent are T3 and T4, which influence the body’s rate of metabolism.
• Parathyroid glands: The parathyroid glands consist of four small glands that are located behind the thyroids in the neck. They influence the calcium levels in the body by producing a hormone called Parathyroid Hormone. Sometimes, when the gland produces excess parathyroid hormones, it can have negative effects such as brittle bones and kidney stones.
• Adrenal glands: The adrenal glands sit atop the kidneys and are no larger than a walnut. These glands produce over 150 hormones that regulate different functions in the body. The most well known is Adrenaline, which triggers the flight or fight response. In other words, this is a stress hormone that helps the organism to either face a dangerous situation or to avoid it altogether.

The phenomenon of change in the path of a beam of light as it passes from one medium to another is called refraction of light.

The cause of refraction is the change in the speed of light as it goes from one medium to another.

A ray of light travelling in air emerges into water, it will bend towards the normal after entering in to water because as ray of light travels from lighter denser medium to higher denser medium, rays get bend towards the normal due to refraction.

Functional Groups: All organic compounds are derivatives of hydrocarbons.
The derivatives are obtained by replacing one or more hydrogen atoms with some other atom or a group of atoms.
The new set of compounds formed after replacement has functions different from the parent hydrocarbon.
Functional group:
An atom or a group of atoms present in the molecules, which determines the characteristics property of the organic compounds, is called the functional group.

The 5R's are

Refuse; this means that 'say no for things '

ex; plastic should refuse

Reduce; decreasing the sources like switch off fans and light, leaking taps, use of paper bags, etc

Recycling; conversation of waste material into new article

ex; paper, metal, glass......

Reuse; using things after finished to other material

ex; Envelop,some bottles like boosts used for keeping some granules....

Repurpose; things that cracked cookery

ex; broken glass used as grow of plants....

It is defined as the natural process that causes the transformation of pure metals to undesirable substances when they react with substances like water or air. This reaction causes damage and disintegration of the metal starting from the portion of the metal exposed to the environment and spreading to the entire bulk of the metal.

There are various methods to prevent corrosion. These include,

1. Electroplating

It is the process by which a metal (I) is coated with a thin layer of another metal (II) using electrolysis. In this way, the new metal coating protects the metal (I) from corrosion.

2. Cathodic Protection

In this process, the base metal is connected to a sacrificial metal that corrodes instead of the base metal. By doing so this sacrificial metal (which is more reactive than the base metal) will give out electrons and get oxidised. The ions thus formed takes part in the corrosion reactions thereby saving the base metal.

3. Galvanization

This process involves coating iron with a thin layer of zinc. It is generally done by dipping iron in molten zinc. The zinc layer coating thus protect the iron inside from corrosion

4. Painting and Greasing

Providing a layer of paint or grease on the metal can prevent the exposure of the metal with the external environment thereby preventing corrosion.

5. Choosing the right material can also help prevent corrosion. Eg: Aluminium and stainless steel are highly corrosion resistant

6. Using corrosion Inhibitor

Corrosion inhibitors are chemicals which when added to the corrosion environment has the ability to cut down the rate of corrosion.

• The non-biodegradable chemicals like pesticides and insecticides enter the food chains in land and aquatic ecosystems and then accumulate progressively at each trophic level. This is known as biological magnification. Example - Species like Shark, Swordfish, Orange Roughy, Tuna, King Mackerel, or Tilefish contain proportionally larger levels of toxic mercury than smaller fish and shellfish.

Movement occurs through the use of pseudopodia, where the cytoplasm pushes the plasma membrane outward or inward, creating blunt, finger-like projections.

There can be multiple pseudopodia at one particular instance, hence, its shape rapidly changes.

Every day more and more people joined him and on 5th April 1930, they reached Dandi. At this time, there were about 50,000 people participating in the march.

The Big Bang Theory is the leading explanation about how the universe began. At its simplest, it says the universe as we know it started with a small singularity, then inflated over the next 13.8 billion years to the cosmos that we know today. The Big Bang theory is a cosmological model of the observable universe from the earliest known periods through its subsequent large-scale evolution. 

In 1600 he discovered not only that the Earth itself was a magnet, but also that magnets could be forged out of iron and that their magnetic properties could be lost when that iron was heated. Two hundred years later, in 1820, Hans Christian Oersted began to explore the relationship between electricity and magnetism.

In 1600 he discovered not only that the Earth itself was a magnet, but also that magnets could be forged out of iron and that their magnetic properties could be lost when that iron was heated. Two hundred years later, in 1820, Hans Christian Oersted began to explore the relationship between electricity and magnetism.

The voltage remains the same across the circuit as it is a parallel connection. So, the current across the upper half of the circuit where the ammeter is connected is calculated as I = V/R = 12.04 (total voltage)/12(Resistance R1) = 1 A. Hence, the ammeter will read 1 A. After connecting the Ammeter you have to give power to the circuit by using Voltage source. When you will connect or start the source you will see the Ammeter indicator will move and will be stopped at a point. Which is your ammeter reading. And you should also take the value of voltage V by using multimeter.

The resistivity of a material is the resistance of a wire of that material of unit length and unit cross-sectional area. The unit for resistivity is the ohm-metre.
The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size.
A good conductor has less resistivity, whereas a bad conductor or insulator has high resistivity.
The resistivity of semi-conductors lies between that of conductors and insulators. The resistivity of a metallic conductor increases with an increase in its temperature, whereas the resistivity of a semi-conductor decreases with an increase in its temperature.