Consider the following part of third period:
Mg,Al,Si,P,S
which of these:
has smallest size?

Which of the following species will have the largest and smallest size? Mg,Mg^(2+),Al,Al^(3+)

Considering the atomic number and position in the periodic table, arrang the following elements in the increasing order of metallic character : Si, Be, Mg, Na, P.

Read the given passage and answers following questions : Zeolites are alumino-silicates that are micro-porous in nature. Zeolites have a honeycomb like structure, which makes them shape-selective catalysts. They have an extended 3D-nelwork of silicates in which some silicon atoms are replaced by aluminium atoms, giving them an Al-O-Si framework. The reactions taking place in zeolites are very sensitive to the pores and cavity size of the zeolites. Zeolites are commonly used in the petrochemical industry. A catalytic reaction which depends upon the pore structure of the catalyst and on the size of the reactant and the product molecules is called shape-selective catalysis. For example, catalysis by zeolites is a shape selective catalysis. The pore size present in the zeolites ranges from 260-740 pm. Thus, molecules having a pore size more than this cannot enter the zeolite and undergo the reaction. In which chemical industry Zeolites used ?

Consider the following species : N^(3-),O^(2-),F^(-),Na^(+),Mg^(2+) and Al^(3+) a) What is common in them ? b) Arrange them in order of increasing ionic radii.

Read the given passage and answers following questions : Zeolites are alumino-silicates that are micro-porous in nature. Zeolites have a honeycomb like structure, which makes them shape-selective catalysts. They have an extended 3D-nelwork of silicates in which some silicon atoms are replaced by aluminium atoms, giving them an Al-O-Si framework. The reactions taking place in zeolites are very sensitive to the pores and cavity size of the zeolites. Zeolites are commonly used in the petrochemical industry. A catalytic reaction which depends upon the pore structure of the catalyst and on the size of the reactant and the product molecules is called shape-selective catalysis. For example, catalysis by zeolites is a shape selective catalysis. The pore size present in the zeolites ranges from 260-740 pm. Thus, molecules having a pore size more than this cannot enter the zeolite and undergo the reaction. What is the pore size of Zeolites ?

Read the given passage and answers following questions : Zeolites are alumino-silicates that are micro-porous in nature. Zeolites have a honeycomb like structure, which makes them shape-selective catalysts. They have an extended 3D-nelwork of silicates in which some silicon atoms are replaced by aluminium atoms, giving them an Al-O-Si framework. The reactions taking place in zeolites are very sensitive to the pores and cavity size of the zeolites. Zeolites are commonly used in the petrochemical industry. A catalytic reaction which depends upon the pore structure of the catalyst and on the size of the reactant and the product molecules is called shape-selective catalysis. For example, catalysis by zeolites is a shape selective catalysis. The pore size present in the zeolites ranges from 260-740 pm. Thus, molecules having a pore size more than this cannot enter the zeolite and undergo the reaction. Upon which factor a catalytic reaction depends ?

Element 'X' forms a chloride with the formula XCl_2 Which is a solid with a high melting point, X would most likely be in the same group of the periodic table as: Na, Mg, Al, Si,

The first ionisation enthalpy (Delta_(i)H) values of the third-period elements, Na, Mg and Si are respectively 496, 737 and 786 kJ mol^(-1) . Predict whether the first Delta_(i)H value for Al will be more close to 575 or 760 kJ mol^(-1) . Justify your answer.