Which has lowest melting point Mcq?

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Which of the following has lowest melting point Mcq?
Which has the lowest melting point?
Which of the following has lowest melting point LiCl nacl KCL Rbcl?
Which of the following has lowest melting point srf2 BeF2 baf2 mgf2?

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Ba
Na
Ga
K
None of the above/More than one of the above.

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Option 3 : Ga

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The correct answer is Ga.

Key Points

Gallium has a very low melting point of 29.76°C.
Gallium is a soft, silvery metal used primarily in electronic circuits, semiconductors, and light-emitting diodes (LEDs).
It is also useful in high-temperature thermometers, barometers, pharmaceuticals, and nuclear medicine tests.
The largest producers of gallium are Australia, Russia, France, and Germany.
Atomic number (number of protons in the nucleus): 31
Atomic symbol (on the periodic table of the elements): Ga
Atomic weight (average mass of the atom): 69.723
Phase at room temperature: solid
Boiling point: 3,999 F (2,204 C)
Number of isotopes (atoms of the same element with a different number of neutrons): 24 whose half-lives are known
Most common isotopes: Two stable Ga-69 (natural abundance 60.1%) and Ga-71 (natural abundance 39.9%).

Additional Information

Atomic Symbol	Name of Metal	Melting Point (°C)	Atomic Number
Ba	Barium	727	56
Na	Sodium	97.81	11
K	Potassium	63.5	19

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Answer

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Hint: The melting point which is also denoted as M.P. Due to the large atomic size of alkali metals, the binding energies of their atoms in the crystal lattice is low. These alkali metals are having a low melting point. The melting point decreases down to the group. Therefore, the melting point decreases from Lithium (\[Li\]) to Rubidium (\[Rb\]).

Complete step by step answer:
- The temperature at which the solid starts melting is called the melting point. This M.P depends upon the intermolecular attractive forces between the molecules or the interatomic forces between the elements. Alkali metals belong to the s- block elements because their outermost electron shell configuration ends with one electron, i.e., outermost s orbital configuration is filled with one electron.
- As we know that alkali metals are the first group elements in the periodic table but just, they differ in the periods from second, third, fourth, fifth respectively. As we descend to the group, the size increases since the shells are increasing according to the configuration. So, the lithium is having the smallest size from the group and caesium is having a large size.
- Therefore, the caesium is having very weak interatomic interactions and results in the metallic bond between two caesium atoms becoming very weak. Hence, the caesium melts at the lower temperature as compared to the other elements except for rubidium. Rubidium is the metal that melts even at a lower temperature than caesium.
- From this, we are able to state that as we move down to the group the melting point decreases.

Hence the correct answer is option \[D.\,Cs\].

Note: The alkali metals are shiny when they are cut freshly. These metals are having a lower melting point than the other group elements. The melting point decreases downwards. These metals react vigorously with water and produce hydrogen gases. As we go down to the group, the reaction becomes more vigorous with water.

Which of the following has lowest melting point Mcq?

Cu has lowest melting point because it has lowest enthalpy of atomisation (i.e., heat required to break the metal lattice to get free atoms) among the elements.

Which has the lowest melting point?

The chemical element with the lowest melting point is Helium and the element with the highest melting point is Carbon. The unity used for the melting point is Celsius (C). Click here: to convert Celsius to Fahrenheit or Kelvin.