Chemistry M.C.Q (1 Marks)

As sodium has highest oxidation potential among all. So it has highest tendency for oxidation reaction and it forms most basic hydroxide.

There are a variety of trace elements present in virtually all potable water, some of which play a role in metabolism. For example, sodium, potassium and chloride are common chemicals found in small quantities in most waters, and these elements play a role in body metabolism.

The diagonal relationship is due to identical sizes of ions.
On moving rightward a period of the periodic table, the size of the atoms decreases, and on moving down a group the size of the atoms increases. Similarly, on moving rightward a period, the elements become more electronegative, whereas on moving down the group the element becomes more positive. These two factors work in opposite direction. Hence the elements that are present diagonally to each other have similar properties like atomic size, electronegativity, density, chemical properties of compounds.

On moving down the group, the atomic number of alkali metals increases. This increases the atomic size, nuclear charge and the screening effect. Hence the ionization energies decrease from lithium to caesium.
Hence, lithium has the highest ionization enthalpy among the alkali metals.

When nitrogen is passed over calcium carbide at a suitable high temperature, we get a mixture called nitrolim which is a nitrogenous fertilizer, which is a mixture of calcium cyanamide and carbon.

It should be light to make aerospace material.
Beryllium has low density and also has high thermal conductivity.

The diagonally opposite elements possess almost similar electronegativities and there fore almost similar electropositive character.

Generally Solvay process is used in the preparation of sodium carbonate.

Alkali metals have low ionization energies due to their larger atomic radii.

Crude sodium chloride is generally obtained by crystallisation of brine solution.

Smaller the cation, higher the charge, more will be tendency to form covalent compound.

The blue colour of the solution of alkali metals in liquid ammonia is due to the ammoniated electron which absorbs energy in the visible region of light and thus imparts blue colour to the solution.

Sodium carbonate, potassium carbonate and ammonium carbonate are soluble in water.
Metallic oxides are insoluble except for those of sodium and potassium which are very soluble and those of calcium, barium, strontium, and magnesium which are only slightly soluble.

Alkaline earth metals are electropositive in nature and always undergo oxidation due to which the other reacting species undergo reduction and thus these metals act as reducing agents.

Hypokalemia is when blood's potassium levels are too low. Potassium is an important electrolyte for nerve and muscle cell functioning, especially for muscle cells in the heart. Your kidneys control your body's potassium levels, allowing for excess potassium to leave the body through urine or sweat.

Alkali metals and their salts impart characteristic colour to an oxidising flame. This is because heat from the flame excites the outermost electron to a higher energy level.

Beryllium carbonate has no natural abundance.

Molten sodium is used in nuclear reactors due to its high thermal conductivity properties, it is used as a coolant i.e. to absorb the heat produced during nuclear fission.

Nitrates of alkaline earth metals are prepared by dissolution of carbonate of alkaline earth metals in dilute nitric acid.

Radium salts are radioactive in nature hence they are used in radiotherapy.

Beryllium's chemical behavior is largely a result of its small atomic and ionic radii. It thus has very high ionization potentials and strong polarization while bonded to other atoms, which is why all of itscompounds are covalent.
They form covalent bonds whereas the other members form of the group form ionic bonds.

When exposed to air, the alkali metals tarnish quickly. This is because, they react with oxygen, moisture and carbon dioxide present in air to form oxides, hydroxides and carbonates.

Smaller size of alkaline earth metal is due to high value of nuclear charge, which increases along a period from left to right.

Hyperkalemia is the medical term that describes a potassium level in your blood that's higher than normal.

Explanation: (D) Molten (fused) state and in aqueous solution
Potassium hydroxide is a good conductor of an electric current in the molten (fused) state and in aqueous solution. When it is in solid state it cannot conduct electricity but it can conduct electricity in aqueous solution state or molten state. This is because it is an ionic compound. Ionic compounds are made of charged ions which are held tightly in solid state but become mobile in molten or aqueous solution state. The movement of these mobile ions between electrodes helps in conducting electricity.

Beryllium does not react with water. This is due to the formation of protective thin layer of hydroxide on the surface of the metal.  

The size of the atoms increases as we move down the group from lithium to caesium. Caesium cation has a large ionic size.
Similarly, the superoxide ion has a large ionic size. These ions form a stable lattice by efficient packing of ions.
Hence, caesium can form superoxide very easily.

Because of their high reactivity towards air and water, alkali metals are kept in kerosene oil.

Molten sodium is used in nuclear reactors due to its high thermal conductivity properties, it is used as a coolant i.e. to absorb the heat produced during nuclear fission.

With the increase in the atomic number of alkali metals, the ionic radius increases due to the increase in the number of the shell, whereas the electronegativity, melting point and first ionization potential decrease.

It is due large 'I' atom, least lattice enthalpy.

Sodium is present in blood plasma in larger quantity. It is present in extracellular fluid and interstitial fluids.
Hence, even though sodium diffuses into the cell due to the concentration gradient, there is a sodium pump which pushes it back again.

Magnesium never reacts with cold water. It only reacts with hot water or steam to form its hydroxide and hydrogen gas is evolved.

As sodium accumulates, the body holds onto water to dilute the sodium. This increases both the amount of fluid surrounding cells and the volume of blood in the bloodstream. Increased blood volume means more work for the heart and more pressure on blood vessels. Over time, the extra work and pressure can stiffen blood vessels, leading to high blood pressure, heart attack, and stroke. It can also lead to heart failure.

Sodium performs a lot of important functions for our body. One of them to aid proper nerve functioning. Thus, the right answer is sodium.

The alkali metals show regular trend in their physical and chemical properties with the increasing atomic number.

Magnesium hydroxide dissolved in water is known as milk of magnesia. It is used as an antacid in medicine.

Its salts are covalent and get easily hydrolysed.

Alkali metals have large atomic size. The close packing of atoms is weak. Hence, they are soft. As the atomic size increases on moving down the group, the strength of the metallic bonds decreases.
Hence, the softness of alkali metals increases on moving down the group.

On moving from top to bottom

Sodium allows your small intestine to absorb amino acids, glucose, and water from the foods you eat. It also affects kidney function, helping to retain nutrients in your body so they are not excreted in your urine.

The metallic lustre exhibited by sodium is explained by oscillation of loose electron.
When light falls on the surface of sodium, the free electron starts oscillating at its mean position and get excited to higher levels. On returning back to lower levels, it emits light in all directions. Due to this sodium has a characteristic metallic lustre.

Calcium carbide is also used for ripening fruit artificially in some countries. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is quite similar in reaction to the natural ripening agent ethylene.

It is because hydration energy dominates over lattice energy.

Because it is more covalent and least ionic among these compounds.

Freshly cut sodium metal has a bright, shiny surface due to the oscillations of free electrons that quickly becomes a dull grey as it reacts with oxygen in the air around it. Over time, the metal becomes covered with a white crust of sodium oxide that prevents further reaction of the metal and oxygen.