What is electronegativity How does it vary in group and period?
The tendency of an atom to attract the shared pair of electrons towards itself is known as electronegativity. Electronegativity increases across a period while it decreases down a group. Atomic radius increases down the group due to addition of new shell.
How does electronegativity increase across a period?
Electronegativity increases across a period because the number of charges on the nucleus increases. That attracts the bonding pair of electrons more strongly.
What is ionization enthalpy How does it vary along the period and down the group?
The amount of energy required to remove an electron from an isolated gaseous atom in the ground state is called ionization enthalpy. Ionization enthalpy increases along the period. Ionization enthalpy decreases down the group.
What are the factors on which ionization energy depends?
Ionization energy depends on two factors: The force of attraction between electrons and the nucleus. The force of repulsion between electrons.
How does the Valency vary in a period from left to right?
Valency increases from 1 to 4 and then reduces to zero when we move from left to right across a period. Number of valence electrons increases from 1 to 8 when we move from left to right across a period.
How does the size of atom vary in a period from left to right?
Experiments have shown that the first case is what happens: the increase in nuclear charge overcomes the repulsion between the additional electrons in the valence level. Therefore, the size of atoms decreases as one moves across a period from left to right in the periodic table.
How does atomic size vary along a period?
Atomic size is the distance between the center of nucleus and the outermost electron in the outer shell. Across a period from left to right there is decrease in atomic size with increase in nuclear charge of the element. Atomic size increases down the group because of addition of extra shell.
Why does atomic size decrease across a period?
Across a period, effective nuclear charge increases as electron shielding remains constant. A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius.
How do the Valency and the atomic size vary along a period?
Atomic size decreases on going along a period from left to right because the electron enters into the same shell, therefore, attraction between nucleus and outermost electron increases and thus atomic size decreases. Valency first increases from 1 to 4 and then decreases from 4 to 0 along a period from left to right.
How do the Valency and atomic size of elements vary while going left to right?
The number of valence electrons increases from 1 to 8 in going from left to right in a period. Thus, the valency increase first from 1 to 4 and then decreases from 4 to 0 while going from left to right along a period in the modern periodic table.
How do the Valency and atomic size of an element vary while going from left to right along a period in the modern periodic table?
On moving from left to right in the periodic table, valency increases up to 4 and then decreases. On moving across a period atomic size decreases because of the electron increases by 1 whereas, the number of valence shell remains the same. Therefore as a result of an increase in nuclear charge, atomic radius decreases.
Which of the following reason correctly justify that chlorine has smaller atomic radius than sodium?
Chlorine has more number of protons than that of Sodium. So, Chlorine’s nucleus size is greater than Sodium. Hence, Chlorine will have smaller atomic radius than Sodium. The distance between the centre of the nucleus to the outermost shell in a particular element is the atomic radius of that element.
How do the following traits change in a period from left to right in the periodic table?
Answer. 1. Atomic size – On moving from left to right in a period the atomic radius decreases.As we move from left to right the atomic number of each succeeding element increases by 1. Valency – On moving from left to right in a period, the number of valence electrons increases from 1 to 8.
What is the trend of Valency in a period ?( 2?
Answer: In a period, the number of valence electrons increase (mostly for light metals/elements )as we move from left to right side. However, in a group this periodic trend is constantly, that is the number of valence electrons remains the same.
How does Valency vary in a group?
The valency of an element is dependent on the number of electrons in the outermost shell of the electron. In a group all constituting elements will have the same valency because they all have the same number of electrons in the outer shells. Across the a period, the number however increase by 1.
Why does nitrogen have Valency 3?
The nitrogen atom has 5 electrons in the outermost shell, so it can accept 3 electrons to fulfil the octet structure. Therefore the valency of nitrogen in NH3 is 3.