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Ans :- Elements are made of extremely small particlescalled atoms. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.

The chemical properties of metals are –

Oxidation

All metals except the noble metals, which is gold and silver react with the oxygen to form basic oxides. In the reaction, the Sodium reacts vigorously with oxygen and generates a lot of heat. For example –

Magnesium (Mg) + Oxygen (O2) —- 2MgO (Magnesium Oxide)

Rusting of Iron

Iron (Fe) + Oxygen (O2) + Water (H2O) ——— Fe2O3(Iron Oxide, is a brown color rust)

Greenish Deposit on the Surface of Copper Vessels

The dull greenish material that is deposited on the surface of copper is a mixture of copper hydro oxide [Cu(OH)2] and copper carbonate (CUCO3) which takes place as –

2Cu + H2O + CO2+ O2——- [Cu(OH)2] + (CUCO3)

Reaction of Metals with Water

The metallic oxides are basic in nature.Metals like sodium (Na) react vigorously with water at room temperature.

2Na + 2H2O ——— 2NaOH + H2(Hydrogen hydroxide)

The active metals like Potassium ( K ) and Calcium ( Ca) reacts with water at room temperature. However, some metals do not react.For example – Iron reacts with water slowly.

Reaction with Acids

Acids react with metals to liberate hydrogen along with the corresponding salt of the metal.

Zinc + Hydrochloric acid —— Zinc chloride + HydrogenOr, Zn + 2HC1 —– ZnCl2 + H2Zinc + Sulphuric acid —— Zinc sulfate + HydrogenOr, Zn + H2SO4 —— ZnSO4 + H2

When a burning matchstick is brought near Hydrogen, it burns with a pop sound.

Reaction with Bases

Metals react with sodium hydroxide to produce hydrogen.

Displacement Reactions

Some metals are capable of displacing other metals from theirsolutions. For example – Zinc ( Zn) replaces copper from copper sulfate solutions.

Copper Sulphate + Zinc ——- Zinc Sulphate + Copper

CuSO4 + Zn —— ZnSO4 + Cu

More active metals displace less active metals from their solution, in general. In this case, Zinc is more reactive than Cu, so it replaces copper ( Cu ) from a copper sulfate solution. Implying the rule, a more reactive metal replaces a less reactive metal, however, a less reactive metal cannot replace a reactive metal.

Chemical Properties of Non – Metals

Oxidation:Non-metals react with oxygen to form oxides which are acidic in nature.

Reaction of Non-metals with Water:Non-metals do not react with water though they may be very reactive in the air.However, some non-metals react with air. For example – Phosphorous.

Uses of Metal

We use metals are for various purposes like for making wires and sheets. For example – Copper and aluminum wires in electrical equipment’s, especially for conduction of electricity.

They are also extensively used in making automobiles, machinery, industrial gadgets, etc.

The metals are used in making utensils and water boilers due to its property of being a good conductor of heat.

Uses of Non – Metal

Non-metals like nitrogen and phosphorus are very useful in fertilizers for better plant growth.

Non-metal like Sulphur is useful in crackers.

We use non-metallike chlorine in purple colored solution on the wound as the antiseptic.

Many non-metals like chlorine, Sulphur, iodine are very useful for medicinal purposes.

Non-metal like oxygen is very essential for our life for respiration.

Chemical Properties of Metals

The density of metals is usually high.Metals are malleable and ductile.Metals form an alloy with other metals or non – metals.Some metals react with air and corrode. ...Metals are good conductors of heat and electricity. ...Generally, metals are in a solid state at room temperature.

Metals loose electrons easilyMetals react with nonmetals produce metal salt and waterMETALS HAVE 1,2,3 ELECTRON IN THEIR VALANCE SHELL

Chemical Properties of Metals. The density of metals is usually high. Metals are malleable and ductile. Metals form an alloy with other metals or non – metals. Some metals react with air and corrode. Metals are good conductors of heat and electricity. Generally, metals are in a solid state at room temperature.

chemical properties of metals the of metals is usually high.

Chemical properties of metals are

1) Metals are electropositive in natureMetals have tendency to loose electron

2) Metals react with acid to form metal salt along with hydrogen gasNaCl + HCl = NaCl + H2

3) Metals react with with water

2)Just to mask some of the tartness or sourness of acid present in the tamarind and to give it a slight sweet flavour.

1)Notappropriately you will get that. It can just tell you about its acidic or basic nature. If the substance is highly acidic or basicinnature then it won't beediblebut if it is very lowinbasic or acidic nature it can beedible.

Crystallization is the process used for the purification of solid substances. It is the process of formation of solid crystals of a substance precipitating from a homogeneous solution. Crystallization refers to the process of precipitating out the pure substance or compound from its solution or from an impure mixture by adding a suitable solvent to it. Crystallisation technique for purification is better than evaporation because:The extent of purification in case of crystallisation technique is very high.Crystallisation does not require very high-temperature conditions, there is no need to boil the solvent.In evaporation, we allow the solution to heat to make the solvent evaporate but this may degrade the solute into some another compound.The technique does not require complex apparatus setup for performing the purification.

Applications:

(i) In the pharmaceutical industry as a purification and separation process for the isolation and synthesis of pure active pharmaceutical ingredients.(ii) It's applied for large-scale productions like food additives.

A network solid or covalent network solid is a chemical compound in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material. In a network solid there are no individual molecules, and the entire crystal or amorphous solid may be considered a macromolecule.

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Lysosomesare manufactured and budded into the cytoplasm by the Golgi apparatus with enzymes inside. The enzymes that are within thelysosomeare made in the rough endoplasmic reticulum, which are then delivered to the Golgi apparatus via transport vesicles.Lysosomesarecalledso because they remove the cellular debris. ...Lysosomesdestroy any foreign organisms…(let it be bacteria or viruses or whatever it maybe) that enter the cell. And so they arecalleddigestive bags. Thus they act asscavengersby killing all the foreign organisms that enter the cell.

They are healthy, they balance between thealthy diet and physical activities.

Mentally Focused, they are positive and are not easily dragged down by daily problem. They handle problems deligently.

They encouraged others, see good in people and work well with them

They take time to take care of themselves

They meditate or pray

They are constantly learning and advancing themselves.

They have good habits

They know what they want and go for it.

They are not afraid of challenges

6+3+1+5 = 15.

nterstitialsdefects are a variety of crystallographic defects where atoms assume a normally unoccupiedsitein the crystal structure. Ininterstitialdefects three or more atoms may share one latticesite, thereby increasing its total energy.

Interstitialcompounds are the one which is used to describe the compound that is formed when an atom oflowerradius sit on theinterstitialhole of any of themetallattice. The empty space that lies in between the molecules are of the puremetalare small as compared to theparent metal.

Voids in solid states mean the vacant space between the constituent particles in a closed packed structure.There are two types of interstitial voids in a 3D structure:

Tetrahedral voids: In cubic close packed structure, spheres of the second layer lie above the triangular voids of the first layer. Each sphere touches the three spheres of the first layer. By joining the centre of these four spheres, it forms a tetrahedron and the empty space left over by joining the centre of these spheres forms a tetrahedral void.In closed packed structure the number of tetrahedral voids is two times the number of spheres.

Let the number of spheres be n.

Then the number of tetrahedral voids will be 2n.

Octahedral voids: Adjacent to tetrahedral voids you can find octahedral voids. So now, what are Octahedral Voids? When the triangular voids of the first layer coincides with the triangular voids of the layer above or below it, we get a void that is formed by enclosing six spheres. This vacant space formed by combining the triangular voids of the first layer and that of the second layer are called Octahedral Voids. If the number of spheres in a close-packed structure is n, then the number of octahedral voids will be n.

Molar mass of Calcium = 40.078 g/mol.

So numbers of moles = 5.00/40.078

=0.125 mol.

Molar mass of Calcium=40.078g/mol. So numbers of moles =5.00/40.078=0.125 mol.

Buffers are the mixture of weak acids and their salts of strong bases (or) the mixture of weak bases and their salts of strong acids. Buffers help to maintain a normal pH of the biological systems. When an acid (or) alkali has added the pH of the solution changes in the absence of buffers. The blood plasma is a highly effective buffer solution almost ideally designed to keep the range of pH of the blood between 7.2 to 7.3.

Correct answer:option (a) Na+ and Ne

The properties of synthetic fibres that make them useful include:

High strength

Resistance to wrinkling

Fast drying

These properties are exploited in making clothes with synthetic fibres.

Answer:conservationExplanation:Wildlife conservation is the practice of protecting wild plant and animal species and their habitat.The goal of wildlife conservation is to ensure that nature will be around for future generations to enjoy and also to recognize the importance of wildlife and wilderness for humans and other species alike.

Hess'sLawofConstant Heat Summation(or just Hess'sLaw)states that regardless of the multiple stages or steps of a reaction, the total enthalpychange for the reaction is the sumof all changes. Thislawis a manifestation thatenthalpyis astatefunction.

Mass of one atom of carbon is 12 times equal to the mass of one atom of hydrogen.

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no. of moles of sulphur=3.2/32=0.10.1 moles of calcium will contain same no. of molecules as no. of molecules contained by 0.1 moles of Sulphur.0.1 moles of calcium = 4gm calcium

Kwof water = [H+][OH-]10-12=[H+][OH-]at 100oC

​Let us assume the concentration of H+ = x

Since each water molecules dissociates into one proton and one hydroxide ion.i.e. the quantity or the concentration of these two ions will be equal in water.[H+] = [OH-]

Therefore10-12= x.x10-12= x2x = 10-6

[H+] = [OH-]​ =10-6

pH = - log[H+]​ = - log10-6= 6 log 10 = 6 ​

1)Euclid's division lemma :

Let a and b be any two positive

integers .Then there exists two

unique whole numbers q and r

such that

a = bq + r ,

0 ≤ r < b

******************************************

Now ,

900 and 270 , start with the larger

integer , that is 900. Apply the

Division lemma , we get

900 = 270 × 3 + 90

270 = 90 × 3 + 0

The remainder has now become

zero . Now our procedure stops.

Since the divisor at this stage is 90.

Therefore ,

HCF ( 900 , 270 ) = 90

each of the microscopic particles, typically single cells, of which pollen is composed. Pollen grains have a tough coat that has a form characteristic of the pollen-producing plant and which can still be recognized in some archaeological deposits.

option c is right.................

Option CThe potential energy of your body is least when you are sleeping on the ground.

TemperatureBasically, solubility increases with temperature. It is the case for most of the solvents. The situation is though different for gases. With increase of the temperature they became less soluble in each other and in water, but more soluble in organic solvents.

PolarityIn most cases solutes dissolve in solvents that have a similar polarity. Chemists use a popular aphorism to describe this feature of solutes and solvents: "Like dissolves like". Non-polar solutes do not dissolve in polar solvents and the other way round.

PressureSolid and liquid solutesFor majority of solid and liquid solutes, pressure does not affect solubility.

Gas solutesAs for gasses the Henry's law states that solubility of gas is directly proportional to the pressure of this gas. This is mathematically presented as: p = kc, where k is a temperature dependent constant for a gas. A good proof of Henry's law can be observed when opening a bottle of carbonated drink. When we decrease the pressure in a bottle, the gas that was dissolved in the drink bubbles out of it.

Molecular sizeThe larger the molecules of the solute are, the larger is their molecular weight and their size. It is more difficult it is for solvent molecules to surround bigger molecules. If all of the above mentioned factors ale excluded, a general rule can be found that larger particles are generally less soluble. If the pressure, and temperature are the same than out of two solutes of the same polarity, the one with smaller particles is usually more soluble.

Stirring increases the speed of dissolvingStirring does not have an affect on solubility of a substance, but everyone knows that if he puts sugar in his tea and does not stir, it will not dissolve. Actually, if we left the tea to stand for a long enough time, the sugar would dissolve. Stirring only increases the speed of the process - it increases move of the solvent what exposes solute to fresh portions of it, thus enabling solubility. As molecules in liquid substances are in constant move, the process would take place anyway, but it would take more time.

TemperatureBasically, solubility increases with temperature. It is the case for most of the solvents. The situation is though different for gases. With increase of the temperature they became less soluble in each other and in water, but more soluble in organic solvents.

PolarityIn most cases solutes dissolve in solvents that have a similar polarity. Chemists use a popular aphorism to describe this feature of solutes and solvents: "Like dissolves like". Non-polar solutes do not dissolve in polar solvents and the other way round.

PressureSolid and liquid solutesFor majority of solid and liquid solutes, pressure does not affect solubility.

Gas solutesAs for gasses the Henry's law states that solubility of gas is directly proportional to the pressure of this gas. This is mathematically presented as: p = kc, where k is a temperature dependent constant for a gas. A good proof of Henry's law can be observed when opening a bottle of carbonated drink. When we decrease the pressure in a bottle, the gas that was dissolved in the drink bubbles out of it.

Molecular sizeThe larger the molecules of the solute are, the larger is their molecular weight and their size. It is more difficult it is for solvent molecules to surround bigger molecules. If all of the above mentioned factors ale excluded, a general rule can be found that larger particles are generally less soluble. If the pressure, and temperature are the same than out of two solutes of the same polarity, the one with smaller particles is usually more soluble.

Stirring increases the speed of dissolvingStirring does not have an affect on solubility of a substance, but everyone knows that if he puts sugar in his tea and does not stir, it will not dissolve. Actually, if we left the tea to stand for a long enough time, the sugar would dissolve. Stirring only increases the speed of the process - it increases move of the solvent what exposes solute to fresh portions of it, thus enabling solubility. As molecules in liquid substances are in constant move, the process would take place anyway, but it would take more time.

the line marked A is the correct answer. as in isochoric process volume is constant , so pressure is directly proportional to Temp

1)Ores are minerals that have a high concentration of a certain element, typically a metal. Examples arecinnabar(HgS), an ore ofmercury,sphalerite(ZnS), an ore ofzinc, orcassiterite(SnO2), an ore of tin (Mineral).

2)Definition ofgangue. 1) Sand, rock, and other impurities surrounding the mineral of interest in an ore.

3)In metallurgy, a flux is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining.

An alloy is a combination of metals and of a metal or another element. Alloys are defined by a metallic bonding character. An alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a defined stoichiometry and crystal structure.

Anisothermal processis achangeof asystem, in which thetemperatureremains constant: ΔT=0.

This typically occurs when a system is in contact with an outside thermal reservoir (heat bath), and the change in the system will occur slowly enough to allow the system to continue to adjust to the temperature of the reservoir throughheat exchange.

Alternate energy sources are the energy sources which aren't/derived from fossil fuels.

We need such sources of energy as fossil fuels take billions of years to replenish and usually pollute the environment. Eg: Solar energy,Wind energy, Tidal energy.

concentration is the extensive property

Now a days Bitumen,a petroleum product is used in place of coal-tar for metalling the roads.

Bitumenis the petroleum product which is used for surfacing of roads these days

bitumen is used to surfacing rods

1.Milk is an emulsion in which both the dispersed phase and the dispersion medium are inliquidstate.

2. Paints include dispersed phase is in solid state whereas dispersion medium is in liquid state.

OSWAAL QUESTION BANK.BCOZ MANY QUESTIONS OF THIS BOOK HAVE BEEN ASKED IN BOARD EXAM

Thank you

As it's an exothermic reactionhence enthalpy will be negativehence b

The Grignard reaction is the only simple method available that is capable of producingprimary, secondary, and tertiaryalcohols. To produce aprimary alcohol, the Grignard reagent is reacted with formaldehyde.