This is a type of eye defect Near sightedness or Myopia is a defect of eye in which the objects present near can be seen clearly but the far ibjects can not be seen by the person suffering from this disease. It can arise due to the following reasons :- 1. Increased length of eye
We can calculate the number of electrons in a given shell by using a simple formula as given below. 2n² Where “n” is the number of shell. For example In case of K shell , n=1 So the number of electrons = 2n² = 2 x 1² =2 So in K shell we have 2
In case of Hexagonal unit cell we have two sides equal , and two angles equal to 90 degrees(right angles) but the third angle is of 120 degrees. a = b ≠ c, and similarly α = β = 90 ̊, ɣ = 120 ̊ But in case of monoclinic unit cell we have unequal sides but
It is the foul smell produced by the oxidation of oils and nuts. Mostly the bitter taste of peanut and food made by frying is due to rancidity . Normally the oily substances which are not covered properly , react with the oxygen of air and get oxidised thus give a foul smell. Removal of
Magnesium is a reactive metal, it reacts with the oxygen of air and forms magnesium oxide. Magnesium oxide makes a layer on the upper surface of the metal. Which makes it difficult for the magnesium to get burnt and give characteristic flame. By using sandpaper we can remove its upper layer for proper combustion reaction
Actually it is a process in which the green plants synthesize their food from the water and carbondioxide in the presence of sunlight and chloroplast. The following reaction depicts the chemical change during photosynthesis.
Today we are in a modern era where a lot modernisation has took place. In the field of metals various metals are mixed to get the desired properties. The alloys are used in transportations , machines , telecommunications and a lot more. Basically the alloy is the homogenous mixture two or more metals and some
The atomic Size is an important property that governs various behaviours of an atom or an element, like valency , electronegativity and metallic character. when we move from left to right the nuclear charge increases at every increase of atomic number. Due to increase in nuclear charge the electrons are attracted towards nucleus with more
Yes it is a chemical change as it involves the formation of ash and releases heat. Which can not be reversed to get fuel. In a chemical change the change of properties take place . For example we can write on paper and can fold it ,but if we burn it we get ash and
Density depends upon the number of particles in a unit area. So it doesn’t matter what kind of particles are used. So it is a physical property.
No, dissolving is a physical process, provided that the substances which are being mixed should not react with each other.
Naming the chemical compounds take a lot of practice and memorising some rules just click here .
This is true that a strong acid HCl is formed in our stomach , but it does not harm the internal tissues or organs. The acid is formed for two major reasons. To carry out the digestion especially the enzyme pepsin requires acidic medium for the proper functioning . The acid acts as a first
Vanadium’s electronic configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d3 the outer shell configuration is 4s2 3d3
Any atom , ion, complex ion, or group of atoms that can donate a pair of electrons are the Lewis bases. for example ammonia(NH3 ) , hydroxide ion(OH – ), chloride ion (Cl – )
Mandleev arranged the elements on the basis of increasing order of the atomic masses of the elements. He divided the 63 elements which were known or discovered at that time. There were 8 groups and 6 periods in his Periodic Table. Most importantly he made cards of every element , and wrote the reactions of
Actually chemical bonding is based on the Atomic number and electronic configuration. And the main thing is valency which is based on the number of outer(valence) electrons. Valency decides that how many bonds can be made by an atom . Thus if you ignore periodic table, you have to learn atomic number and electronic configuration
The answer is simple, like you are hungry you can pay more to get the food than that of the person who is less hungry, Similarily here the non metals want electrons thus they spend the energy more , or they release the energy. By this they lose the energy. So smaller is the size
Chemical change is a change in which a new substance is formed which is have totally new properties . And during rusting of iron, the iron oxide is formed that will not show the shine of metal, will not be a good conductor of electricity etc. thus rusting is a chemical change.
Ar, Argon is having the highest ionisation energy in 3rd period. This is due to the fact that it belongs to noble gases , and their outer shell is complete and they are enough stable. So to bring out the electron by applying energy is not an easy task.
The covalent compounds have low melting and boiling points. There is a reason behind this phenomenon. In case of covalent compounds the molecules are non-polar and even if there is a polarity in the molecule, that is also just for a moment. Thus each molecule exists as a discrete particle which do not have affinity
The enzymes increase the surface area and makes it available for reactants to come closer and react. Thus this makes it easy for the reactants to react faster and thus the rate of chemical reaction increses.
To determine the chemical symbol of an element we follow 2 main rules given below :- 1. The symbol of every element is expressed with capital letter. 2. If symbol includes more than one alphabet , then the first alphabet will be in capital case and second will be in lower case.